Linksys Media Hub NMH305

Storage is a crucial part of the digital lifestyle: We all need a place to put our stuff, and we need a way to access those files easily. Linksys has tried a few storage products in the past, but the Media Hub is its most ambitious effort. While it's not exactly a small business server that lets you set up user accounts – like the HP MediaSmart EX487 – and can't compete with the robust RAID and back-up options on Netgear ReadyNAS devices or those by Buffalo Technology, it has one glowing attribute: it's easy to use. Like most Apple products including the still viable Time Capsule, the Media Hub assumes you are not a certified Microsoft engineer or someone who carries USB key drives in your pocket 24x7. It's a smart product that eases you into the deeper features, with only a few caveats.

Setting up the Media Hub takes all of about three minutes. Connect one Ethernet cord to your router, turn it on, and you're done. Because the drive supports UPnP and works well with Windows, Apple iTunes, the Mac (thanks to Bonjour), and even Linux, you can expect to see the drive on your network without installing a driver or fussing with an IP address. Only when you do want to dive into the advanced features will you need the included setup CD or to access the drive's IP.

This NAS matches the styling of the new Linksys Multi-Room Home Audio gear – which is to say, it's gray and black and nothing too special compared to more elegantly designed network-attached storage devices. The difference between a media player you'd stick next to an HDTV, and this product, is that it will likely sit in a back closet somewhere. The Media Hub has two USB ports, one on the front and one on the back. There are very few buttons and lights. The NMH305 base model ships with one 500GB SATA drive and has one open bay. There's a power light and drive activity light – Linksys plans to release two additional models with higher capacities and an LCD screen that reports on drive status.

Performance on the Linksys Media Hub is just ho-hum – it's not going to set any speed records. About 6GB of MPEG-4 movie files took six minutes to transfer to the Media Hub, whereas the same transfer took 3 minutes to send to a home-built Windows Home Server and only 1 min 40 seconds to copy to the HP MediaSmart EX487 server. A 700MB collection of photos and documents took 50 seconds to write to the drive and 50 seconds to read, about 15 seconds longer than it took on the HP MediaSmart. The drive really showed some pokey behavior when we performed a full back-up of a desktop, which took about ten hours for about 200GB of data. The Media Hub has a gigabit Ethernet port, so it should be no slouch, but a real server adds some extra features to speed up disk copies.

source : reviews.digitaltrends.com

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Networking Topology

Think of a topology as a network's virtual shape or structure. This shape does not necessarily correspond to the actual physical layout of the devices on the network. For example, the computers on a home LAN may be arranged in a circle in a family room, but it would be highly unlikely to find a ring topology there.

Network topologies are categorized into the following basic types:

• bus
• ring
• star
• tree
• mesh

More complex networks can be built as hybrids of two or more of the above basic topologies.

Bus Topology

Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.

Ethernet bus topologies are relatively easy to install and don't require much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.

Ring Topology

In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.

To implement a ring network, one typically uses FDDI,SONET, or Token Ring technology. Ring topologies are found in some office buildings or school campuses.

Star Topology

Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch, and router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.

Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

Tree Topology

Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.

Mesh Topology

Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing.

A mesh network in which every device connects to every other is called a full mesh. As shown in the illustration below, partial mesh networks also exist in which some devices connect only indirectly to others.

Summary

Topologies remain an important part of network design theory. You can probably build a home or small business computer network without understanding the difference between a bus design and a star design, but becoming familiar with the standard topologies gives you a better understanding of important networking concepts like hubs, broadcasts, and routes.

source : compnetworking.about.com

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MAKE OMNI ANTENNA

Introduction

Most of the designs on the web for 2.4 GHz omni antenna seem to involve brass tubing and lmr-400 cable, none of which are readily available to me. I then found a coax only design for 444Mhz that was based on the same idea. The only reasonable cable I could get my hands on was RG-213 from Maplin. By scaling the 444Mhz design up to 2.4 Ghz and using RG-213 I thought I'd have a go. In order to get about 6db gain from the antenna, it would need 8 sectors, with a 1/4 wave section at the top and a fly-lead with N-connector at the bottom. It should take about 2-3 hours to build an antenna using this design, but don't worry if it takes longer, you will get quicker, especially as you only need to make the jig once.


Most of the designs either had toroid magnets or a decoupler on the fly-lead of the antenna. However the location of the decoupler seems different in each design, and some designs quoted a decoupler length of 1/4 wavelength, others were !/4 wavelength times the velocity factor of the decoupler tube (brass tube quoted at 0.95). I've tried most locations and can report that without proper testing kit I can see no difference in the Signal to Noise ratio between having a decoupler and not. I decided to not bother as it simplified the design. If anyone knows a good reason why you must have a decoupler then I would love to know (especially if you know where it should be exactly). If you want to add a decoupler, please do, I found using 15mm or 22mm copper tube and a 15mm or 22mm end stop made a good design, just needing to be soldered together to get the right length, and a hole drilled in the end of the end stop to fit the cable.


Each sector of the antenna needs to be a 1/2 wavelength long multiplied by the velocity factor of the cable. The velocity factor of RG-213 is 0.66 . If you decide to use different cable (such as LMR-400) then you need to get the velocity factor of that cable (which will be different), and recalculate all the dimensions.

V * C 0.66 * 299792458
1/2 wavelength = ------ = ---------------- = 0.0405m = 40.5mm
2 * F 2 * 2441000000

V = Velocity Factor of RG213 = 0.66
C = speed of light = 299792458
F = Frequency of Signal = 2441000000 (middle of 2.4ghz range)

The 1/4 wave element is not adjusted by the Velocity factor, as it is in the open, so works out at just 31mm long giving a total antenna length of 355mm + fly-lead. (Thanks to Oscar for correcting me of this.)
Getting the parts

All of the parts are available cheaply from either Maplin and any diy shop.

* 1m RG-213U cable (available by the meter from Maplin). This is enough for 2 antenna. Buy more for whatever flylead length you want.
* N connectors, Depending on what you want to connect to , use either male or female connectors, and inline or bulkhead. Remember inline connectors need to fit 10mm diameter RG-213 cable
* 20mm pvc conduit (available from any diy store) Has a 20mm inside diameter, and 22mm outside.
* 22mm pipe clips (depending on how you want to mount the antenna), pipe clips make it easy to mount and unmount, or use the proper conduit brackets (but they seem a little expensive).

You don't need any special tools

* mm rule for measuring !
* junior hacksaw
* stanley knife
* pliers
* standard soldering iron (don't need a heavy duty one) and solder
* off cuts of wood to make a jig to aid soldering
* bench or vice to hold cable while you cut it

Cut the pieces

After much trial and error, I found that the neatest way to cut the cable is actually with a junior hacksaw. It gives a much cleaner finish than wirecutters. Each sector consists of a short length of RG-213 cable, with the central core sticking out each end.



When building the antenna, the exact length of each piece of RG-213 is not that important, it is the overall length of each sector that counts. I found that cutting the cable to 37mm with 6mm of core sticking out each end, gets enough overlap to easily solder the segments together. If you allow 1mm for the width of the hacksaw when cutting the sectors apart, it means you need 37 +6 +6 +1 = 50mm of cable for each sector making 8sectors + 1/4wave section come to 420 mm of cable for the antenna + cable for the fly lead.

The best way to cut each sector is to make the cuts where each end of the sheathed section of the sector will be, before making the cut between each sector. The picture below shows the top 3 sections of the antenna, and the 1/4 wave section, showing the order that the cuts should be made.



The best way to make the cuts is to mark them out on the cable first. When sawing the cable it has a tendancy to deform and bend, so lightly sawing round the outside sheath first, but not cutting through, helps give a guide to the cutting for real. I use the junior hacksaw to gently saw round the cable sheath to make the mark for each section.

The first mark will be at 31mm from the end, which is for the 1/4 wave section at the top. Once you have made the mark, it is time to cut round the cable. You want to cut through the sheath, shielding, and just into the central insulation, but not into the central copper wires. You may need to practice a bit first, but you should be able to feel as you cut through the shielding into the central insulation. By leaving plenty of sheathed section either side of the cuts, the shielding stays in place when being cut.



Now with pliers, gently twist off the end 31mm of sheath & shielding

This should leave the cenral insulator exposed. Using the stanley knife score round through the central insulator, but not too hard, or you will cut the central cable. Now twist off the insulation. You should be able to see the twist in the central cable through the insulation, which will show you which way to twist off the insulation, resulting in the central core twisting more tightly.


The next mark is 37mm down (68mm from end of the cable) and is the cut for other end of the sheathed section of the top sector. The next mark is 13mm down (consists of 6mm core from each sector and 1mm for cut between sectors) (81mm from end) and is the top of the sheathed section of the second sector. The next mark is 37mm down, then 13mm, then 37mm, and so on and so forth until you have each of the sheathed sections marked out.

You can now start making the cuts, remembering to only cut through the sheath, shielding and just into the central insulation. First make the cut at 37mm down, then the next cut a further 13mm down. You may find that some of the shielding pulls out when you make this cut, as the 13mm length of sheath cannot hold the shielding tight enough. Don't worry, it doesn't matter.



Now you are ready to cut off the top sector from the cable. You want to cut through the whole cable at the mid point of the two cuts you have just made, that is about 43.5 mm from the end of the sheath, or 74.5 mm from the end of the cable. See position 4 in the diagram above. Just saw carefully the whole way through the cable.

Now you can pull off the sheath and shielding from the each end.


Now score round the insulation as you did before, being careful not to cut the central cable

Now carry on making cuts 37mm down from the end of the sheath, and then 13mm further down (50mm from the end of the sheath), and then cut through the cable in the middle of the two cuts. Another sector made. You will need eight sectors in total. Make the same cuts as usual for the eighth sector as it will make top of the flylead as well. Now you have all eight sectors you need to check round the end of each sector to make sure that none of the shielding is touching the central cable, as odd strands can get left.

Now you need to make a gentle V shaped cut with the stanley knife, at each end of the sectors, to expose the shielding, which is where the central core of the next sector will be soldered.


Make sure that the V cuts at each end of the sector line up, othwise, when you come to solder the antenna together, the whole thing will be twisted all around. Once you have all eight sectors finished, its time to put them together.
Build a Jig
If you do not have a handy helper to hold the sectors together, then you will find it easier to make a small jig from offcuts of wood, to hold the sectors together as you solder them. The clamps on the right hand side of the picture need to be no more than 30mm long. The base board of the jig, needs to extend out to the right long enough to take the whole length of the completed antenna, as it will need to support it during the soldering, as the antenna is not rigid enough to support itself.


Don't make the clamps too tight, as you need to be able to easily lift the cable out after it has been soldered.


When you are readly to solder the sectors together, you need to take care , that each sector is correctly spaced. The overall length of each sector needs to be 40.5mm , measure from one end of the shielding of the sector you are adding, to the same end on the next sector, and slide the sectors together/apart until the distance is 40.5 mm. Try to get it as accurate as you can, as it affects the direction the antenna transmits in if you get it wrong. There should be a small 3mm gap between the sheaths of each sector.





Once you have soldered each sector together, lift it up, turn it over, and move it down the clamp ready for the next sector. This results in a nice straight antenna. When soldering, remember to heat both the shielding and core so that the solder runs smoothly and fixes them together.

Once complete, test the cable with either a bulb and battery or a multimeter. The center of the fly lead should form a circuit to the 1/4 wave section, and the shield of the flylead to the shield of the top section. Now test that there are no crossed connections, by ensuring there is no circuit between the center of the flylead and the shielding of the top sector, and no circuit between the 1/4 wave section and the shielding of the flylead.

Now fix the N connector of your choice onto the end of the fly lead. The type of connector you use depends on what you want to connect to. I use inline connectors, but you could use any connector you like. Slide the antenna into a length of conduiting. It should be a snug fit, you may need to gently ease it in. Now find an old soft drink bottle top, and pop it on the top end of the antenna. Voila one complete antenna ! Securing the antenna in the conduit is best left until you are ready to mount it somewhere. You can cut 5cm slots in the bottom if the conduit, and use a jubilee clamp to grip the flylead, or drill a hole through the conduit and use a cable tie to hold the fly lead, or use a bulkhead mount connector on a botle cap, and glue it to the bottom of the conduit, or glue the flylead in place. It's up to you.
Testing

I will assume you are connecting the antenna to a wireless card in a laptop, and connecting to an accesspoint somewhere. You will need to a signal to noise meter to examine the signal strength. Most wifi cards come with software that does this. Now its time to test that the antenna actually works. This can be harder than it sounds, as unless you can remove the existing aerial from the card or ap, you can't tell it is using your new homebrew antenna. Well wrapping the existing antenna completely in 6-8 layers of tinfoil, has a dramatic reduction on signal strength, now connect the antenna, and the signal should go back up. Remember that omni antenna send out the signal horizontally, so don't test it from the room below your access point. Hopefully you should see that your new antenna actually works. There are three ways to test the gain of the new antenna

* Use spectrum analyser in a professional radio lab
* compare the gain of your new antenna, to the gain of a known antenna (Not the pcmcia card)
* Carry out an empirical range test with your new antenna

If you have access to a spectrum analyser I'd love to know your findings. If you have an existing omni or yagi antenna, then you can compare the snr readings between the two antenna. Remember to do the test outside, as bouncing the signal off walls can really give odd results. Try to stand as far away from the antenna as possible when doing the test, as even moving near it can change the results a lot. Position the two antenna in the same place for the test. Don't try and compare the snr of your new antenna to that of the wireless card in your laptop, as just by turning the laptop round, or lifting it up, or holding it, can dramatically change the snr. Try it and see what I mean. If you don't have another antenna, then wander down your street until you are out of range. Now wander back towards your AP, and wait for the laptop to chime that it has made a connection. Note how far from home you are. Try it again, with the laptop connected to the new antenna. Remember to keep the antenna vertical. I found carrying them in a bag with the antenna poking out the top works well. Try not to hold the antenna, as this will change the snr. You should now be able to pick up your AP about twice as far away, assuming there are no new massive obstacles.

If you have a go at making this antenna, and get it working, drop me an email (address at bottom of page) and let me know how you found building it, whether you've found a simpler way, and ... be honest ... how long it took.

source : wireless.gumph.org

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Top review of HSDPA Modem

Here discuss about review HSDPA modem that may be tested that technology. This review I got from the people who already used. From here we can see what the feature, or the bad of HSDPA modem. I hope this review can be helping you to use HSDPA modem.

The Sierra Wireless AirCard 881U

At first glimpse, the AirCard 881U from Sierra Wireless is a beast of a gadget. Big, ugly, and surprisingly heavy, the USB modem isn't nearly as stylish as the other modems.
Similarly annoying is the install process. If you're a Windows user, it's easy -- simply pop the disc into your machine and follow the screen prompts. But if you're a Mac user, it's much more difficult. To install it on my Mac OS X 10.4 MacBook, I had to go to the Sierra Wireless Web page's support section and download the correct software for my operating system. Once that download was complete, I was finally able to install the software, restart my computer, and connect to AT&T's 3G network.

The AirCard 881U's software was delightfully easy to use and far more bearable than the ridiculous install. To connect to the 3G network, you need only to open the program and click the Connect button. In a matter of seconds, the modem is up and running and you're free to surf.
I was pleasantly surprised with the speed I experienced while browsing the Web. Simple pages like Google (NSDQ: GOOG).com opened in just a few seconds with 3G connectivity and more complex Web sites like ESPN.com opened about twice as fast as my EDGE-connected cell phone, but about 10 seconds slower than my Wi-Fi connection. All in all, I was getting about 1.0 Mbps on the downlink and roughly 375 kbps up.
Although 3G connectivity with the AirCard 881U was a great experience, it suffers from the same limitations that all USB modems do: it's governed by the data coverage that wireless carriers provide. And unless you live in a big city or around a densely populated area, don't expect 3G wherever you go. In fact, I quickly found myself surfing at EDGE speeds when I ventured away from the metro area.
The Sierra Wireless AirCard 881U is a generally lackluster USB modem that's bloated, too heavy, and more of an eyesore than anything else. And although connecting to 3G was delightfully easy and the price tag -- free after mail-in rebate -- is attractive, AT&T's $60 per month data plan and the AirCard 881U's aforementioned issues should make you think twice before picking it up.
source: www.informationweek.com

Sierra Wireless 875U HSDPA USB Modem

by:Sascha Segan
Blaze across the virtual globe with the Sierra AirCard 875U, the fastest, most flexible way to connect your laptop PC to AT&T's high-speed network and to dozens of other computer systems in foreign lands. High-speed wireless connection solutions are available from three major carriers, in four different forms. You can get them from Sprint, Verizon, or AT&T, and they come either as chips embedded in laptops, as PC Cards, ExpressCards, or USB dongles.
USB dongles such as the AirCard 875U are less compact than the other options, but they're a lot more flexible. Since pretty much every PC has a USB port, it's easy to move them between computers. The 875U's SIM card slot is also relatively easy to access under its front cover. This lets you move your SIM between the dongle and your phone more readily than you could with a card.
About the size of an old-school pager, the 875U has a USB jack that pops out of the modem's body on an easy-to-release latch. Plugged into your laptop, it sits upright like a periscope, with unobtrusive green power and signal lights. There's an easy-to-access external antenna port covered by a little rubber plug on the side.
The 875U operates with AT&T's standard LaptopConnect plans. One option costs $69.99 per month for unlimited use in the U.S., and the other will set you back $139.99 per month for unlimited U.S. data plus 100MB of data overseas, with additional overseas MB $5 each. Those prices are on a par with what's offered by Sprint and Verizon.
AT&T's network, meanwhile, has come a long way since I first looked at it last year. AT&T uses HSDPA technology, which also works in dozens of countries overseas, including most of Western Europe. Over the past year, AT&T has extended its network to most major U.S. cities and metro areas. The current HSDPA spec allows for 3.6-Mbps downloads and 384-Kbps uploads, in theory.
In reality, we got average speeds of just over a megabit for downloads on the 875U, with download speeds peaking at 1.63 Mbps. Uploads averaged 275 Kbps, but with a strong signal frequently hovered around 350 Kbps. That's broadband speed, although if you're used to wired or Wi-Fi broadband, you'll still feel that Web pages load slowly because of the average 240-millisecond latency on network requests. The 875U supports the 850, 1800, 1900, and 2100-MHz bands, so you'll be able to get access in Buffalo or Berlin, provided you're on the right service plan.
When the 875U isn't in 3G range, it drops down to AT&T's EDGE network, which offers speeds of around 80 to 120 Kbps down. I generally don't recommend EDGE cards for laptop users for a different reason—EDGE transmissions tend to make some laptop speakers buzz annoyingly. If you're traveling primarily through EDGE country, I'd recommend tethering a phone to your laptop via Bluetooth instead.
The 875U proved faster than the competing AirCard 875 PC Card and Option GT MAX 3.6 Express in head-to-head download tests. It's also faster than older models such as the AirCard 860. The competition was tight. Of 35 downloads, the 875U was the fastest on 15 of them; the ExpressCard was faster on 14 tries. Differences in signal strength between the 875U and the Option ExpressCard were negligible.
Rather, it's the AirCard's flexibility I like. As a USB device, it's easy to plug and unplug at will, and the SIM card slot is easier to extract cards from than on the ExpressCard. Better still, the 875U is compatible with Microsoft Windows XP, Vista, and Mac OS 10.4.9, though its driver isn't integrated into the Mac OS. You have to download a "Sierra AirCard Watcher" application from Sierra's Web site.
source: www.pcmag.com

Huawei E272

he E272 enables uplink speeds of up to 2Mbps and download rates of 7.2 Mbps. Within HSPA network, the device will facilitate fast internet browsing, instant access and the uninterrupted ability both to upload and download data. Combining cutting edge technologies with sleek design, customers can look forward to enjoying high-speed wireless access, both at home and on the go. The plug-and-play featured devices are compatible with Windows (Vista and XP) and Mac OSX, whether run on a PC, laptop or handheld device.

Benefits:
Boost your efficiency with 14 times faster download speeds than standard 3G.
Work more effectively with 22 times faster upload speeds than standard 3G.
Plug and go with any laptop or desktop, including Macs.
Enjoy seamless coverage at home and roaming abroad.
Connect with speeds of up to 7.2Mbps.

Specification:

* The USB Modem works with all laptops including Macs. It can also be used with any PC.

Microsoft Windows requirements:
* Standard USB interface
* Microsoft Windows 2000, XP or Vista
* Microsoft Internet Explorer 5.5 or higher
* At least 50MB free disk space and 128MB RAM

Apple Mac requirements:
* Standard USB interface
* Optimised for Power PC based Macs and Intel based Macs
* Mac OS X Panther 10.3.9 or higher

Technical Specification:
* 3G (UMTS/HSDPA/HSUPA) Frequency supported 2100Mhz
* EDGE/GPRS Frequency supported 900,1800 and 1900Mhz
* Support for USA/Canada :Yes For GPRS/EDGE at 1900MHz

Auto switch frequency: YES
WLAN network supported: NO
Apple Mac compatible: Yes , with special VMC software for Mac OS

source : hkoffer.com

Huawei E220 USB Modem

Been using Huawei E220 for around 1 month, I could say that this modem does its function well. No issue related to hardware. The installation process completed with auto-run in Windows Operating System, no need any installation CD, just plug the modem to any USB port and it will prompt you to start the software installation.
The connection is stable, however it depends on your network provider as well. in my home area, around Pangkalan Jati, Kalimalang. It could run very well for nights and days, without any need of reconnection.
This modem was launched back in 2006. Maximum speed is 3.6 Mbps, you could set this modem to use 3G only signal, or 3G prefered if you are not sure you will get a good reception of 3G signal.
Bought it for Rp.1.450.000 in a store at ITC Kuningan Jakarta, I am surprise to see this modem sold for Rp.1.250.000 at a small computer store in Palembang .
I use this modem along with Telkomsel Flash Unlimited Package which has virtually unlimited capacity but with limited maximum speed of 256Kbps (up to 3Gb per-month, before the speed is reduced to 64Kbps).
Connection of max 256Kbps is quite decent for me, allows me to check web mail, update anti virus, connect to my company VPN - Virtual Private Network, and do some downloads (never yet try to download big files though). However because the speed limitation of Telkom Flash unlimited package, I have never test the maximum speed of this modem.
I have tested this modem along with Telkomsel Flash in area of Kalimalang Jakarta (HSDPA connection - Very Good), Kuningan Jakarta (HSDPA connection - Very Good), Plaju - Palembang (HSDPA connection - not to good, some re-connection needed, sometime could not connect), Tuban - East Java (EDGE connection, but stable).
The whole body of this modem is plastics. There is no lock on the SIM card port, so you need to be careful not to drop this modem to the floor. It might spit out your SIM Card. Also don’t step on it, I believe it will break a part.
If you are a mobile person who need a notebook computer to work and be online, or you need a HSDPA modem which you could use on your home PC and notebook computer; and you just can’t rely on with your HSDPA smartphone for some reasons, I recommends Huawei E220.
source :myweathertop.wordpress.com

NOVATEL OVATION MC930D/MC950D

Nowadays, Internet connectivity ranks high in our hectic everyday schedules, regardless of the fact that we have places to visit, people to meet, and things to get done. It’s not surprising that we’re practically as dependent on the Internet as we are on electricity. Thus, we need absolute on-the-road mobility with universal connectivity. Today we’re going to review Novatel’s Ovation MC950D HSPA mobile broadband USB modem.
The Ovation MC950D is a 3G modem based on the latest HSUPA, HSDPA, and UMTS technologies. HSUPA stands for High-Speed Uplink Packet Access, HSDPA stands for High-Speed Downlink Packet Access, and UMTS represents Universal Mobile Telecommunications System technology. These are key technologies of 3G, which offers the most cutting-edge high performance data access speeds.

resumably, the Ovation MC950D and its younger sister, the MC930D, are the world’s smallest modems. This is possible thanks to their latest innovative design, which is similar to the USB stick form factor standards. It fits comfortably in a pocket. And most importantly, backwards compatibility isn’t neglected because the modem can switch back to quad-band GPRS/EDGE 2G technologies when tri-band UMTS 3G signals aren’t reachable.
The modem supports up to 7.2mbps downlink data access speeds and 2.1mbps uplink. The aforementioned are architectural limitations by design because these speeds are 100% dependent on carriers and network operators. This gadget doesn’t bring you the Internet “for free;” you need to sign up with a carrier for a plan or account in your area, and then you receive an UMTS HSUPA/HSDPA compatible SIM card.
Novatel Wireless optimized this modem for North America, Europe, and Japan, but technically worldwide support is possible as long as there is the necessary network coverage on the supported bands. It is platform independent so it works fine on Microsoft Windows, MAC OSX, UNIX, and Linux operating systems.
There are lots of network partners that are selling the Ovation MC950D modem. More often than not, these partners are network operators and, therefore, you can also sign up with them right away. For this review, the modem was acquired through Vodafone so it sports the “Vodafone” logo instead of Novatel Wireless. The red SIM card is also from Vodafone.
Nevertheless, we can’t continue before examining its price. The Ovation MC950D is available for around £159.80, €210, and US$320 at the time of writing. Sure, it’s not a bargain, but you need to pay the price for innovation and universal connectivity. Additionally, the plans can go up to €30 per month, but mostly this depends on features - whether it’s unlimited or not, your area, how the network looks there, etc.
source : www.devhardware.com

Sierra Wireless' Compass 597

Unlike its older brother, the AirCard 881U, the Sierra Wireless Compass 597 is an attractive addition to any computer. Better yet, the company's smallest USB modem offers a fully equipped device that easily outshines other Sierra Wireless products and competes admirably with the Novatel USB727. And with a beautiful black finish and an attractive light on the end to tell you it's in use, you won't be put off by this modem's looks.
The Compass 597's installation on my MacBook was quick and easy. In a matter of seconds, I popped the modem into my computer, installed the software, restarted my computer, and connected toSprint (NYSE: S)'s Mobile Broadband Network without a hiccup. Much like the Novatel USB727, the installation process was seamless. But no disc was required to install the software. Instead, the Compass 597 has all drivers and software already installed on it, which speeds and simplifies installation.
While connected to Sprint's Mobile Broadband Network, Google loaded quickly and detailed sites like ESPN popped up at an adequate, but noticeably slower speed than the load times I witnessed on Verizon's BroadbandAccess and AT&T's 3G network. According to Speedtest.net, I achieved speeds of about 875 kbps down and 300 kbps up.
The Compass 597 uses Sprint's SmartView software, which is easily the best package on the market and much better than the tools I used on the other modems. Aside from GPS tracking and the ability to search points of interest in your area, the tool also allows you to test upload and download times, get an updated view of Sprint's Broadband coverage map, manage your Sprint account, and access the company's Digital Lounge service.
Sprint's Digital Lounge allows you to buy anything from screensavers for your phone, to music, TV, and games. Even though most of the content is too expensive to justify a purchase, it's nice to have the option.
The Sierra Wireless Compass 597 is a fine USB modem that won't take up too much room in your pocket, nor look too foolish hanging off the side of your computer. And with a fantastic software package, it's not a bad idea to pick this one up -- if you don't mind spending $100 (after rebate) for the modem plus $60 per month for 5 GB of data.
source : www.informationweek.com


VODAFONE HUAWEI E172


Vodafone has partnered with Chinese telecoms equipment maker Huawei to create a USB 3G modem the size of a flash drive, but still capable of accessing HSUPA mobile data networks.

The mobile broadband USB modem stick, the Huawei E172, is Vodafone's smallest ever plug-and-play device and significantly smaller than any previous data card or 3G modem it has offered. It is compatible with Windows (Vista and XP) as well as Mac OS X.

Vodafone will offer the stick alongside its existing, E220 USB modem which was released last year. "They are exactly the same inside," said Vodafone spokeswoman Bryony Clow. "It's just that the E172 has a smaller form factor. We are looking to sell both as the different forms will appeal to different people. We'll be pushing the stick, but the modem will be available as well."

The E172 supports uplink speeds of up to 1.44Mb/sec and download rates of 7.2 Mb/sec, which they claim is theoretically 14 times the speed of standard 3G. However, the 7.2Mb service is currently only supported within Central London and at certain UK airports. This will increase as Vodafone continues the rollout of HSUPA to the rest of its 3G network.

"Vodafone was the first to improve download speeds with HSPDA, the first to increase upload speeds with HSPUA. And now we're pushing the boundaries of usability even further with a compact modem design," said Kyle Whitehill, enterprise director at Vodafone.

The mobile broadband market is getting more competitive, with network operators cutting prices and adding value to service plans to entice both consumer and business customers. Last week IT PRO reported that Carphone Warehouse and mobile network 3 had joined forces to offer a £35-a-month bundle comprising a mobile broadband service, bundled text messages and a Dell laptop.
source :www.itpro.co.uk

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Guide to GSM, GPRS, 3G, EDGE, HSDPA

It can be confusing trying to understand the differences between the various mobile connectivity options listed in the specifications of smartphones and touted by the mobile networks as the best way to connect to the internet. In this guide we will try to summarise these technologies and point out the advantages and disadvantages of each technology.

GSM

GSM (Global system for mobile communications) is the standard by which the vast majority of mobile handsets work in Europe and is becoming dominant in other parts of the world with over 2 billion people currently using the system. When you purchase a mobile or smartphone it is important to understand what frequencies are used by each technology because manufacturers and networks have a tendency to quote these figures with little explanation as to what they mean.

The majority of GSM networks use 900MHz and 1800MHz but in the US the 850MHz and 1900Mhz are prominent. If these are quoted the phone will be classed as a tri-band phone and can be used in Europe, the US and many other territories (provided your SIM is enabled). If you require mobile access in the Far East and areas such as Scandanavia you will need to check with your mobile provider because at the minimum a quad-band phone will be required and in some areas only a phone purchased in the country will work.

Most GSM phones are primarily used for voice but can be used for mobile internet access via the GPRS Core Network.

GPRS

GPRS is a system used to transmit data at speeds of up to 60 kbits per second and is a battery friendly way to send and receive emails and to browse the internet but in these days of broadband connectivity it will be seen as slow by some. To set up GPRS connections on your smartphone you will need to obtain specific information from your mobile provider to input into your phone. Most are happy to provide this information and some manufacturers such as Nokia offer pre-configured files that you can install onto your phone for your network.

GPRS is a tried and tested system and is therefore very reliable for standard mobile data use and will suit people with moderate data needs. Once you have the required settings in place you can use the network whenever you like and it requires no further adjustment as it works in the background of your internet enabled applications.

EDGE

EDGE (Exchanged Data rates for GSM Evolution) is a recent development based on the GPRS system and has been classified as a '3G' standard due to the fact that it can run at up to 473.6 kbits per second. If a smartphone is EDGE compliant it can be used for heavy mobile data transmission such as receiving large email attachments and browsing complex web pages at great speed. To use EDGE cell sites must be modified to accept transmissions of this type so coverage can be patchy in certain areas- it is a technology well worth having built in to any smartphone though.

3G

3G was initially marketed as a way to make video calls on the mobile network but is also a highly efficient way of browsing the internet and communicating on your smartphone using voice over IP and by email and instant messaging. Most UK and some European networks now have 3G networks and with speeds similar to EDGE it is fast becoming a common way to connect while on the road.

In areas where 3G coverage is poor the handset will constantly try to find a 3G signal and this can have a dramatic affect on battery life. Some phones handle constant 3G enablement well but some can have their battery life reduced by up to 50% so it is worth checking that your potential purchase is able to cope with this. At this time though 3G has good coverage and enables high speed internet access from your phone and is fast becoming a standard for mobile connectivity.

HSDPA

HSDPA (High speed Downlink Packet Access) is a technology based on the 3G network which can support speeds of up to 7.2 mbits per second. In reality you will most likely get a top speed of around 3 mbits but this is useful for mobile TV streaming and other high end data transmissions. To use HSDPA your phone must be able to support the technology and of course you will need to be located within range of a cell site that has been upgraded to offer the service.

The key to all of these technologies is to understand what your typical usage will be and which of the above suit your needs. It could also be worth future proofing your needs because well connected devices often cost little more than phones with basic connectivity.

source : www.clove.co.uk

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2.5G, 3G, 3.5G and 4G technology

What is 4G?

4G takes on a number of equally true definitions, depending on who you are talking to. In simplest terms, 4G is the next generation of wireless networks that will replace 3G networks sometimes in future. In another context, 4G is simply an initiative by academic R&D labs to move beyond the limitations and problems of 3G which is having trouble getting deployed and meeting its promised performance and throughput. In reality, as of first half of 2002, 4G is a conceptual framework for or a discussion point to address future needs of a universal high speed wireless network that will interface with wireline backbone network seamlessly. 4G is also represents the hope and ideas of a group of researchers in Motorola, Qualcomm, Nokia, Ericsson, Sun, HP, NTT DoCoMo and other infrastructure vendors who must respond to the needs of MMS, multimedia and video applications if 3G never materializes in its full glory.

Motivation for 4G Research Before 3G Has Not Been Deployed?

• 3G performance may not be sufficient to meet needs of future high-performance applications like multi-media, full-motion video, wireless teleconferencing. We need a network technology that extends 3G capacity by an order of magnitude.

• There are multiple standards for 3G making it difficult to roam and interoperate across networks. we need global mobility and service portability

• 3G is based on primarily a wide-area concept. We need hybrid networks that utilize both wireless LAN (hot spot) concept and cell or base-station wide area network design.

• We need wider bandwidth

• Researchers have come up with spectrally more efficient modulation schemes that can not be retrofitted into 3G infrastructure

• We need all digital packet network that utilizes IP in its fullest form with converged voice and data capability.

Comparing Key Parameters of 4G with 3G

	3G (including 2.5G, sub3G)	4G
Major Requirement Driving Architecture	Predominantly voice driven - data was always add on	Converged data and voice over IP
Network Architecture	Wide area cell-based	Hybrid - Integration of Wireless LAN (WiFi, Bluetooth) and wide area
Speeds	384 Kbps to 2 Mbps	20 to 100 Mbps in mobile mode
Frequency Band	Dependent on country or continent (1800-2400 MHz)	Higher frequency bands (2-8 GHz)
Bandwidth	5-20 MHz	100 MHz (or more)
Switching Design Basis	Circuit and Packet	All digital with packetized voice
Access Technologies	W-CDMA, 1xRTT, Edge	OFDM and MC-CDMA (Multi Carrier CDMA)
Forward Error Correction	Convolutional rate 1/2, 1/3	Concatenated coding scheme
Component Design	Optimized antenna design, multi-band adapters	Smarter Antennas, software multiband and wideband radios
IP	A number of air link protocols, including IP 5.0	All IP (IP6.0)

What is needed to Build 4G Networks of Future?

A number of spectrum allocation decisions, spectrum standardization decisions, spectrum availability decisions, technology innovations, component development, signal processing and switching enhancements and inter-vendor cooperation have to take place before the vision of 4G will materialize. We think that 3G experiences - good or bad, technological or business - will be useful in guiding the industry in this effort. We are bringing to the attention of professionals in telecommunications industry following issues and problems that must be analyzed and resolved:

• Lower Price Points Only Slightly Higher than Alternatives - The business visionaries should do some economic modeling before they start 4G hype on the same lines as 3G hype. They should understand that 4G data applications like streaming video must compete with very low cost wireline applications. The users would pay only a delta premium (not a multiple) for most wireless applications.

• More Coordination Among Spectrum Regulators Around the World - Spectrum regulation bodies must get involved in guiding the researchers by indicating which frequency band might be used for 4G. FCC in USA must cooperate more actively with International bodies like ITU and perhaps modify its hands-off policy in guiding the industry. When public interest, national security interest and economic interest (inter-industry a la TV versus Telecommunications) are at stake, leadership must come from regulators. At appropriate time, industry builds its own self-regulation mechanisms.

• More Academic Research: Universities must spend more effort in solving fundamental problems in radio communications (especially multiband and wideband radios, intelligent antennas and signal processing.

• Standardization of wireless networks in terms of modulation techniques, switching schemes and roaming is an absolute necessity for 4G.
  

• A Voice-independent Business Justification Thinking: Business development and technology executives should not bias their business models by using voice channels as economic determinant for data applications. Voice has a built-in demand limit - data applications do not.

• Integration Across Different Network Topologies: Network architects must base their architecture on hybrid network concepts that integrates wireless wide area networks, wireless LANS (IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.15 and IEEE 802.16, Bluetooth with fiber-based Internet backbone. Broadband wireless networks must be a part of this integrated network architecture.

• Non-disruptive Implementation: 4G must allow us to move from 3G to 4G.

source : www.mobileinfo.com

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Router Review

This posting discuss about router. Many router product on the world. We never know what the peformance of it. So I compare routers review. The compare product is Linksys WRT56GS, Netgear WGT624, D-Link DI624, Dell Wireless 2300, Microsoft MN-700, and Buffalo AirStation WLA-G54. I hope you can choose the best router after read it.

Linksys WRT54GS

review by: Xiao Ming Wu

Editors' note: The rating and/or Editors' Choice designation for this product has been altered since the review's original publication. The reason for this is simply the general improvement of technology over time. In order to keep our ratings fair and accurate, it's sometimes necessary to downgrade the ratings of older products relative to those of newer products. (12/9/04) The Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster makes it easy to set up a typical home or office network, and it comes with all the documentation you need to get it up and running. It touts a wealth of advanced networking and security features, and it's fast, especially in networks with both 802.11g and 802.11b connections.The illustrated Fast Start guide for the Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster walks you through the basic setup, which includes connecting the router to your computer and broadband modem, configuring all the computers on the network to work with the router, and configuring the router. The Fast Start guide is more thorough than others we've seen, with plenty of images and screenshots illustrating the setup process. We were glad to see brief explanations of basic networking terms, such as the difference between static and dynamic IP addressing and what to do if your DSL provider uses PPPoE. The guide also describes how to connect to the WRT54GS's browser-based configuration tool if you need to tweak the router's configuration--for example, to supply the router with a static IP address. No quick-setup guide can cover all possible networking scenarios, but Linksys's step-by-step guide does an excellent job rounding up the usual suspects and making it easy for most homes and small offices to set up a network in a few minutes. In most cases, you need only to plug in the router and connect the cables. For more complicated setups, Linksys includes a thorough user guide detailing the WRT54GS's diverse features.Although the Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster is easy to set up, you'll find a number of advanced features and configuration options under the hood. The Linksys WRT54GS's browser-based configuration tool gives you access to the router's networking and security settings, such as DHCP server and client settings, firewall settings, and wireless encryption settings. The router also comes with two types of firewalls. One is a Stateful Packet Inspection (SPI) firewall that makes sure packets are part of a legitimate connection; the other is a NAT firewall that effectively hides computers behind the router. You can lock your network down even tighter by configuring the router to block services such as FTP and Telnet. A DMZ function located on the configuration tool's Applications and Gaming tab lets you place one computer outside the firewall, which can be useful for Internet gaming and videoconferencing. The Linksys WRT54GS also lets you set up access-control policies that grant Internet access to specific computers on your network at predetermined times of day and days of the week. If you telecommute, the router's VPN pass-through support will help get you to work. The Linksys WRT54GS router also has good wireless security. You can configure it to use WEP or WPA. WPA is stronger than WEP, but it's important to have both options, because you may want to connect to older 802.11b devices that lack WPA support. We also like that you can turn off the beacon on the WRT54GS's integrated 802.11g access point. This helps protect you from uninvited guests by stopping the access point from advertising its presence to the world. The Linksys WRT54GS router comes with removable antennas, giving you the option of attaching high-gain antennas to the unit to increase its range. Our only gripe was that the router lacks a mounting bracket.The Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster is one of a growing number of wireless routers touting proprietary speed enhancements. Like the D-Link DI-624 and the Netgear WGT624, the WRT54GS SpeedBooster router includes a technology (in this case, Broadcom's Afterburner) that substantially increases wireless network performance. The enhancements kick in only if all the devices on the network are playing by the same proprietary rules; otherwise, the device scales down to standard 802.11g speeds. We think that this limitation makes the SpeedBooster enhancement (and similar Turbo or Super-G offerings from vendors such as D-Link and Netgear) more of a marketing gimmick than a significant feature. Proprietary solutions depend on networks molded out of homogenous gear, limiting your purchase choices and tying you to a single vendor. On the other hand, the Linksys WRT54GS Wireless-G Broadband Router with SpeedBooster does a fine job supporting standards-based equipment from other vendors, even older 802.11b gear. In CNET Labs' mixed-mode tests, which measure throughput when both 802.11g and 802.11b transmissions occur simultaneously, the WRT54GS delivered the fastest speeds we've seen, clocking in at 25.8Mbps. The Linksys also went the distance, stretching as far as 200 feet in our range tests.

Netgear WGT624
review by: Allen Fear

The Netgear WGT624 108Mbps wireless firewall router is a good example of the advantages and disadvantages of bleeding-edge technology. It offers nearly double the throughput of standard 802.11g devices and increased range to boot. Plus, the WGT624's fast throughput over distance combined with its support for portions of the 802.11e draft standard make it well suited for streaming media over your wireless connection. Other advanced features, such as an SPI firewall and support for Dynamic DNS, make the WGT624 a good choice for techies who are looking for a high-performance wireless router and are willing to perform an occasional firmware upgrade. (Netgear has already released one firmware upgrade for the router that fixes some bugs and enhances performance.) If the idea of router maintenance doesn't appeal to you, consider the Dell Wireless 2300, which lacks the speed of the WGT624 but is easier to set up, or the Microsoft MN-700, which automatically checks for firmware upgrades. The Netgear WGT624 108Mbps wireless firewall router comes with all the hardware and software you'll need to set up your network. In addition to the router, the product package contains an AC power adapter, a rubber stand, an Ethernet cable, a printed installation guide, and a CD containing a comprehensive reference manual. We like the compact design of the WGT624. The router's rubber stand and built-in mounting bracket on the bottom panel help you position the device for optimum range. The LEDs on the front of the unit let you monitor data passing across the WGT624's Ethernet and wireless interfaces. Plug the router in, connect it via the Ethernet cable to your broadband modem, and you've installed the WGT624 hardware. The network installation is a little less straightforward, and the printed guide may leave some in the lurch. The guide asks you to manually reconfigure the network settings of each computer if necessary, then it refers you to an online resource to learn how to do this. In contrast, the Dell Wireless 2300 and the Microsoft MN-700 include software that automatically configures the network settings for the router and any connected computers, making these instruments better suited for those new to networking. After you connect the WGT624 to your local network, the router's browser-based Smart Wizard automatically detects the type of Internet service you have and directs you through the rest of the installation. The Netgear WGT624 108Mbps wireless firewall router has a good feature set that meets the needs of both advanced users and those with little or no networking experience. The WGT624's browser-based configuration tool is easy to navigate and offers features tailored for family networking. The tool is password-protected and includes a content-filtering section that gives you control over the types of sites your computers can access, letting you restrict access based on keywords, service types, IP addresses, and times of day. The WGT624 also displays detailed logs of the Web sites that your computers have accessed or attempted to access, which lets you police the types of traffic passing through your network. The router includes two different types of firewalls: network address translation (NAT), which hides your computers' IP addresses behind the router's IP address, and stateful packet inspection (SPI), which checks individual data packets to make sure they are part of a legitimate connection. Together, these firewalls provide strong security against most attacks originating from the Internet. The WGT624 also supports WEP and the stronger WPA encryption scheme. We wish that the WGT624 supported wireless distribution system (WDS). Limited range is a problem for many home networking environments, and WDS makes it easy to expand your coverage area by simply adding a repeater, such as the Buffalo WLA-G54C, to rooms where your signal is weak. The WGT624 has other performance enhancers under the hood that make it especially well suited for streaming media. Portions of the 802.11e draft specification are built into the router's firmware. These new features ensure that streaming media applications, such as the voice and video links in a teleconference, aren't interrupted by a simple file transfer. This means that you can participate in the teleconference over your wireless connection and download data from the Internet without suffering degradation in the audio or video quality of the links. The most noteworthy feature of the Netgear WGT624 108Mbps wireless firewall router is its inclusion of Super G Technology (link is a PDF file), which boosts the router's speed to nearly twice the tempo of standard 802.11g devices'. A recent firmware upgrade allows the router to switch dynamically to support standard 802.11g and 802.11b devices when they enter the network. CNET Labs tested the router's throughput with various adapters concurrently, and the results are impressive. The WGT624 ran circles around the U.S. Robotics USR8054. Better yet, the Netgear router delivered fantastic range in our indoor tests, providing stable connections as far as 225 feet away.

D-Link DI624
Review By: Allen Fear

Editor's note: The rating and/or Editors' Choice designation for this product has been altered since the review's original publication. The reason for this is simply the general improvement of technology over time. In order to keep our ratings fair and accurate, it's sometimes necessary to downgrade the ratings of older products relative to those of newer products. (12/14/04) When we first reviewed the D-Link DI-624 AirPlus Xtreme G router a year ago, we were unimpressed, but that was then, and this is now. The new DI-624 is about half the size of the original and twice as fast. It also comes with an improved quick-installation guide, a more comprehensive manual, stronger security features, and an excellent support package that includes a long, three-year warranty. Few routers are as easy to set up as the DI-624, but if the thought of typing an IP address into your browser's address bar makes you sweat, then consider the less powerful but easier to use, Microsoft MN-700. On the other hand, if you're looking for a fast router with excellent range and a bushel of features, such as a configurable firewall, parental controls, top-notch wireless security, and VPN pass-through support, then look no further. With a current street price of about $70, the DI-624 is a great buy for both home and small office networks. For a router with such an advanced feature set, the D-Link DI-624 AirPlus Xtreme G router is easy to set up. The package includes everything you'll need: the router; a CD-ROM containing a manual and warranty info; an Ethernet cable; and a 5V DC power adapter. The new DI-624 is compact, about the size of a medium-size paperback, and its bottom panel doubles as a mounting bracket, making it easy to attach to a wall or the ceiling. Unfortunately, the DI-624 doesn't come with a stand for vertical positioning, which is a feature we like in the Netgear WGT624. The hardware setup is a snap, literally. Connect the DI-624 to your broadband modem with the cable that came with your modem, use the Ethernet cable in the package to connect the router to your computer, and you're done. Although D-Link doesn't offer an automated configuration routine like the one you'll find with the Dell Wireless 2300 and the Microsoft MN-700, the DI-624's network setup is about as easy as it gets; it's one of the smoothest setup routines we've seen. The printed quick-installation guide walks you through every step of the installation process, with screen shots and instructions for both Mac OS X and Windows XP that show you how to connect to the DI-624's browser-based configuration tool. The browser-based tool itself includes a five-step setup wizard that automatically detects your Internet connection and configures security for your wireless network. The explanations and instructions in the printed quick-installation guide seamlessly complement the wizard, addressing each step in the process. The D-Link DI-624 AirPlus Xtreme G router is chock-full of features for both homes and small offices. Auto MDI/MDIX ports in the router's Ethernet switch eliminate the need for costly crossover cables and make the DI-624 easy to connect to other hubs and switches. The router also comes with a removable antenna, so you can expand your coverage area by adding an antenna. The router also features parental controls that include URL filtering, domain blocking, and access scheduling by day of the week and time of day. If you play games over the Internet, you can use the DI-624's special gaming mode, which adjusts the firewall to allow for network entertainment. For connections that demand even less restrictive access, such as videoconferencing, you can use the router's DMZ feature, which lets you place a single computer outside the router's firewall. If you telecommute, the DI-624 also supports VPN pass-through for both PPTP and IPSec. With a firewall that is more configurable than most we've seen, the DI-624's security is top-notch for a consumer router. You can turn the firewall on and off, a feature missing from the Microsoft MN-700 and one that can be important for troubleshooting and allowing certain types of connections. You can also create a list of rules that let you allow or deny specific types of traffic between your internal network and the Internet. For example, you can block UDP traffic from the Internet targeted for a specific port on one of your computers. The DI-624 heaps on wireless security features. The router supports not only 64- and 128-bit WEP encryption, but also WPA and ironclad 802.1x authentication via a RADIUS server. The D-Link DI-624 AirPlus Xtreme G router is one of the best-performing routers we've seen. Like the Netgear GT624, the D-Link DI-624 comes equipped with an Atheros AR5002 chipset, the secret to its blazing throughput and great range. If you already have a DI-624, you can upgrade the router's firmware to the latest version to take advantage of the new performance enhancements. The so-called 108Mbps firmware is currently available only for DI-624s with a label on the bottom that reads "H/W Ver.:C1." At close range, the DI-624 clocked in at 44.4Mbps. That's about twice as fast as a typical 802.11g router and just under the Netgear WGT624's speed of 47.1Mbps. The DI-624 also matched the WGT624 in range, surpassing other 802.11g performers with a record-setting 225 feet. We were less impressed with the DI-624's performance in a mixed environment with 802.11b devices. Here, the router was able to eke out only 11.6Mbps at close range, noticeably less than the 18.2Mbps demonstrated by the Dell Wireless 2300.

Dell Wireless 2300
Rreview By: Patrick Unnold

Editors' note: The rating and/or Editors' Choice designation for this product has been altered since the review's original publication. The reason for this is simply the general improvement of technology over time. In order to keep our ratings fair and accurate, it's sometimes necessary to downgrade the ratings of older products relative to those of newer products. Dell's Wireless 2300 broadband router offers superior performance and a well-rounded feature set suited for the home user. Windows 2000 and XP users, as well as novices, will like the streamlined installation, which nearly runs itself (other operating systems are supported, but not as seamlessly). The Wireless 2300 supports both 802.11b and 802.11g and touts an excellent array of security options, including WPA, WEP, SSID blocking, stateful packet inspection (SPI) firewall, and parental controls. You can also link the router to two additional Wireless 2300 routers to increase your 802.11g coverage area. This is the most polished 802.11g router we have seen to date. The initial setup of the Wireless 2300 is simple and quick, especially for those with Windows 2000 or XP systems. Inserting the accompanying CD starts the Setup Wizard. After a quick scan of your network, the Setup Wizard automatically configures the settings for both your computer and the Wireless 2300. With the Setup Wizard making all of the networking changes for us, we connected quickly and were surfing within just a few minutes. The process takes a bit longer with other OSs, but the included user guide walks you through the process. Changing the router's configuration requires the Web-based configuration tool; unfortunately, it's a little convoluted. For example, the Setup Wizard warns you to lock down the wireless network by changing the SSID, enabling WEP or WPA, and turning off SSID broadcasts. The first two items are easily found in the Basic section of the configuration tool, but users must make their way to the wireless settings of the Advanced section to turn off SSID broadcasts. The Wireless 2300 is packed with features and security, and it supports 802.11g and boasts an eye-pleasing exterior design. The sleek, silver-and-black chassis has wall-mounts built into its base. The clearly labeled indicator lights show activity for the Internet connection, each of the four ports on the built-in 10/100 switch, and the wireless LAN. The Wireless 2300 offers the latest in security options for wireless networking. It supports the new WPA encryption scheme as well as the older 64/128-bit WEP standard. There's no support for 802.1x authentication, but the router does offer an expansive MAC address feature that can be applied to all clients of the Wireless 2300, whether wired or wireless. Stateful Packet Inspection, NAT, packet filtering, and intruder-detection alerts offer a high level of Internet security. Additional security features include port forwarding, which allows for both a DMZ computer and the forwarding of specific packets to specific computers. The well-rounded parental-control feature lets you block Internet access for specific computers by time of day. You can also limit Internet access completely or restrict it to a list of Web sites. Another great feature is the router's ability to create a wireless bridge with up to two additional Wireless 2300s. This lets it function as a bridge and a repeater, similar to the Buffalo WLA-G54. The Dell Wireless 2300 offers some of the best 802.11g throughput rates we've seen to date, second only to the U.S. Robotics USR8054. In our tests, the throughput rates for 802.11g peaked at 23.5Mbps for 802.11g, and those for mixed-mode (with both 802.11g and 802.11b clients transmitting simultaneously) reached 18.2Mbps. The throughput degradation over distance is also very good. Most notably, both the Wireless 2300 and the USR8054 outperform their competitors in mixed-mode performance by more than a factor of two. The Wireless 2300 has a few limitations. The user guide indicates that the Wireless 2300 can support only 16 wireless clients or 64 NAT clients; in addition, having more than 20 simultaneous users of any type degrades the device's overall performance. Most home users will never stress the Wireless 2300 to this extent, but small offices could begin to hit the performance ceiling if their network grows large enough.

Microsoft MN-700
review by: Patrick Unnold

Microsoft's new 802.11g MN-700 wireless broadband router is designed so that even a novice user can expand a home network easily, but it has a few shortcomings compared to the Editors' Choice-winning Dell TrueMobile 2300. The setup process and the configuration utility are very user-friendly, and Microsoft's support options will help with most problems you might encounter. It offers most features that home users need, and the Setup Wizard automatically turns on wireless security--a unique and much-needed detail. Its range is excellent. Experienced users will be frustrated by the lack of advanced configuration options and wireless bridge support, however. Like the Dell TrueMobile 2300's streamlined installation routine, the MN-700's Setup Wizard gathers the necessary network information automatically before configuring both your wireless network adapter and the MN-700. The Setup Wizard supports all Windows platforms; a nonautomated, browser-based interface is available for other OSs. We uncovered a bug in the Setup Wizard software that prevented the application from completing normally when we attempted to use a workgroup name that contained a period. Microsoft tech support worked quickly to determine the cause and promised a fix in a future release. The MN-700's documentation is excellent. In addition to the printed installation guide, you get a thorough, printed user guide with a lengthy troubleshooting section, as well as detailed instructions for nonstandard installations, such as using the MN-700 as an access point instead of as a router. You use the Broadband Network Utility, which you install on one of your networked machines during setup, to check network status and adjust the MN-700's configuration. Like the Setup Wizard, the Broadband Network Utility is novice-friendly; it's easy to navigate, with clear help information on each screen. The utility also checks automatically for updates, making it simple to keep the firmware current. The MN-700's impressive security setup includes one unique and much-needed touch: wireless security is enabled during setup--no other product we've seen does this--and other security features, such as Stateful Packet Inspection (SPI) firewall and NAT, are always on. Additional security features include parental controls, client filtering, 64/128-bit WEP, 256-bit WPA, DMZ, MAC address filtering, and detailed logging. While the MN-700 boasts 802.11b/g Wi-Fi certification and an impressive feature set for home users, it doesn't offer much advanced configurability. For instance, it lacks options such as support for RADIUS and wireless bridging, which are available on similarly priced products, such as the Buffalo AirStation router. Also, you cannot control the output wattage for the wireless network or adjust the security level of the firewall. The only option available for configuring the firewall is a check box for enabling ICMP blocking. The Dell TM2300 gives you more control of the firewall. The MN-700's hardware features mirror those of most other home routers. The device sports a rotating external antenna and a four-port 10/100 Ethernet switch that autosenses crossover cables as well as the line speed. The MN-700 is designed for the desktop and is not well suited for mounting on a wall or a ceiling. With a healthy throughput of 21Mbps in 802.11g mode and nearly 12Mbps in mixed 802.11b/g mode, the MN-700 outperforms many of the wireless broadband routers we've tested. However, the MN-700 still falls short of the throughput we've seen in the broadband routers released since the 802.11g specification was ratified, specifically the US Robotics 8054 and the Dell TrueMobile 2300. Thanks no doubt to its rotating external antenna, the MN-700 showed solid performance over distance, outperforming even the US Robotics 8054 and the Dell TrueMobile 2300. In our tests, the MN-700 achieved a throughput of nearly 6Mbps at a whopping 175-foot distance in 802.11g mode, and it didn't completely drop off until it approached 200 feet. That gives it about a 25-foot advantage over the Dell and US Robotics products. The extra distance could be important, because unlike the Dell TM2300, the MN-700 cannot be linked via a wireless bridge.

Buffalo AirStation WLA-G54
Reviewed by: Patrick Unnold

A single wireless router or access point can't always cover every room in a house. The Buffalo WLA-G54 wireless bridge gives you a plethora of features and options for expanding your home or office network without stringing cable. It includes a four-port switch for wired clients, and it supports both 802.11b and 802.11g standards. Because it's externally identical to the Buffalo AirStation 54Mbps wireless broadband router we've previously reviewed, it suffers from the same flaws, including limited mounting options and hard-to-see LEDs for the four-port switch. The Buffalo WLA-G54 installs easily to a wired network, but connecting it to another Buffalo AirStation to create a bridge is harder than it should be. When you start the initial configuration, you can designate either a wired or wireless connection; the quick-setup guide has decent instructions for both. In either case, you have the option of connecting to the WLA-G54 via the Client Manager software included on the CD-ROM or a browser such as Internet Explorer or Netscape. Once you've connected a computer to the WLA-G54, you're ready to integrate it into your network by assigning IP addresses and the ESS-ID and configuring security options. The browser-based configuration tool includes wizards for WEP settings and MAC address restrictions, plus an advanced-configuration page that gives you direct access to all of your options. If you use the WLA-G54 to create a wireless bridge to another Buffalo AirStation, you must register the MAC address of each Buffalo access point, router, or bridge on your network under the WDS section of the configuration screen. The terse documentation fails to cover this process thoroughly. The Buffalo WLA-G54 wireless bridge distinguishes itself from other bridges, such as the Linksys WET54G, with its Wireless Distribution System (WDS) support. This lets the WLA-G54 act as a wireless repeater with up to six Buffalo WDS-enabled AirStations, such as the Buffalo AirStation router on a single network, making it an ideal solution for large houses or apartment buildings. Because WDS is not a standard, however, it doesn't work with non-Buffalo products. A swivel cover on the top of the back panel conceals an MMX connector. For larger sites, the WLA-G54 also works as a point-to-point or point-to-multipoint bridge that's capable of communicating with up to six other Buffalo base stations--a quick, easy way to extend your wired network or improve your existing WLAN coverage. The WLA-G54 is packed with the latest security options to lock down your network. It offers both 64- and 128-bit WEP encryption, but the WLA-G54 also supports WPA and 802.1x. Remembering some of the WLA-G54's more complicated settings is easy because the bridge lets you save its configuration on a local PC. This feature, along with the recessed reset/initialization button on the back of the WLA-G54 that resets it to factory defaults, is very handy in case you find yourself locked out of the device. The only feature we didn't like were the unit's LEDs, which are positioned on the bridge's side and difficult to see. The performance of your Buffalo WLA-G54 will depend greatly on how you've configured it and what it is doing on your network. As an 802.11g access point, the WLA-G54 offers good range, with consistent and decent throughput up to around 100 feet before a swift decline. The Linksys WET54G performs better, but the WLA-G54 offers WDS, which the WET54G lacks. Assume a throughput hit when you configure the WLA-G54 (or most any wireless bridge) as both a bridge and an access point for wireless clients. That's because in a bridged network, configuration packets have to be transmitted over the WLAN once to get to the WLA-G54 bridge, then again from the bridge to the next Buffalo AirStation or client adapter connected to your wireless network.

source:www.review.cnet.com

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