Wi-Fi

10 things you should know before you buy an 802.11n wireless device

If you've spent any time in your local electronic shop, you are sure to have seen a rash of Pre-N and Draft-N (802.11n) wireless products. Before you get caught up in a rush of new product frenzy and plunk your money down, take a few minutes and look at exactly what you are buying.

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If you've spent any time in your local tech shop, you are sure to have seen a rash of Pre-N and Draft-N wireless products. Before you get caught up in a rush of new product frenzy and plunk your money down, take a few minutes and look at exactly what you are buying.

1 - MIMO

One of the big advantages of 802.11n is MIMO. MIMO is short for Multiple Input / Multiple Output. MIMO breaks the data transmission down to multiple parts that are sent separately to the client, where they are reassembled. One of the requirements for this then is multiple antennas to send and receive the data. This system has the advantage of extending the range of wireless, along with increasing the capacity that can be carried by the signal. MIMO is implemented in almost all Draft N and Pre N specs. The use of MIMO in these devices has, for the most part, greatly extended the range of these devices. Unfortunately, there are still debates ongoing about the finalization of MIMO itself, as the 802.11n spec is not ratified yet.

2 - Standard not fully ratified

IEEE has not fully ratified the standards for 802.11n. This means that the technical details of 802.11n have not been decided upon. The original draft for 802.11n was voted on earlier this year and soundly rejected, receiving only 46 percent of the needed 75 percent of votes to be accepted. Draft 2.0 of the spec is scheduled be debated and approved in March of 2007. Items adhering to this spec can be labeled as Phase 1 Draft N. These items will be compatible with each other (unlike many current pre-n and draft n components). The final ratified standard will probably be ratified in early 2008. Of course, if no Draft 2.0 can be agreed upon in March 2007, this will push the schedule for all of this back.

3 - Equipment cannot guarantee N compatibility

As the final spec of 802.11n is not fully ratified, it is impossible to guarantee that any equipment sold as Pre-N or Draft-N will be compatible with the final spec. Many manufactures on banking on the assumption that compatibility can be achieved by firmware updates to their equipment. Currently the only vendor offering a full replacement warranty should there equipment not be compatible with the final spec is Asus. You can view information on their WL-500W router here, and you can view the details of their guarantee here.

4 - Huge speed increases over 802.11g

The final 802.11n will undoubtedly boast a great speed increase over 802.11g. This boost will almost assuredly make wireless faster than 100mb Ethernet. Currently most Pre-N and Draft-N equipment are already showing great speed increases. The speed they operate though varies based on manufacturer and equipment. The advertised speeds vary from 100mb to 200mb. If you truly need greater speed, be very careful in your shopping to make sure you are getting the fastest speed possible.

5 - Backward compatibility with previous wireless standards

While IEEE has announced that any final spec for 802.11n will include backward compatibility for 802.11b and 802.11g this specification is not finalized. With this being the case, there can be no guarantee of backward compatibility for current Pre-N and Draft-N gear. While most of the products currently on the market offer backward compatibility, how they implement it varies from vendor to vendor. Due to this, there can be (and have been reported) many instances where gear labeled as backward compatible, have not been fully backwardly compatible with equipment from other vendors.

6 - Draft-N and Pre-N gear may not be compatible with Draft-N and Pre-N gear from other vendors

Currently in the Draft 1.0 of the 802.11n spec, there is nothing to guarantee compatibility among equipment. If you choose to use Pre-N or Draft-N gear you will need to buy all of your equipment from a single vendor. While interoperability may be promised, there is no way to guarantee this. The Draft 2.0 spec of 802.11n will include interoperability standards for the release of Phase 1 Draft-N gear.

7 - Testing has shown MIMO systems not based on Draft-N standards can be significantly faster than systems based on Draft-N

Real world testing has shown that highest possible speeds using MIMO can be achieved by not sticking to the Draft-N specifications. What this means is that if you are truly searching for the fastest possible wireless connection, do not force your search to just N class products, but products that use MIMO.

8 - Draft-N gear is driven by marketing

It has been several years since any new development was made in consumer grade Wi-Fi. This has lead to a certain degree of stagnation within the market. The advent of Pre-N gear has given companies something to latch onto in an attempt to offer their customers something new. While there are undoubtedly benefits (in speed and range) to using this new gear, you are also putting yourself in line for potential problems. You really need to weigh your actual needs before jumping on the bandwagon of a "not ready for prime-time" technology.

9 - Potential to interfere with existing Wi-Fi

One of the issues with MIMO is that it uses a wide spectrum (40MHz) to send its data. Currently only three (1, 6, and 11) of the available channels in the current 2.4 GHz band are considered to be non-overlapping at this spectrum. However, under a powerful signal they can overlap. What this means to you is that if you have multiple wireless networks running, your Pre-N gear will need to be on one of these 3 channels, possibly necessitating a change in your current wireless networks. Also, you will want to plan for the overlap if possible, by moving your current networks to channels not sequential to 1, 6, and 11.

10 - Issues with media streaming devices

One issue that has been reported with Draft-N and Pre-N gear is that it appears it have some issues with various media streaming devices. This is an extremely perplexing issue, as of the goals of 802.11n was the ability to stream high definition media wirelessly. Whether this is due to issues in the Draft 1.0 specs, or if it's an issue with the current generation of media streaming devices remains to be seen, but at the moment a wired connection remains your best bet for streaming.

12 comments
Mark W. Kaelin
Mark W. Kaelin

If you bought one of these devices are you happy with it? Has your business organization considered 802.11n products? Are you concerned about possible changes to the standard?

harriuk
harriuk

I bought Linksys Draft-N Router and 2 usb adapters and hav no problems running it at home. I can often get a 300Mbps signal, I'm often streaming DVD quality media over it with no probs.

abhinav
abhinav

Of course everyone in the similar domain is more or less excited about 11n and associated products. But since the specs are still not finalized, there would always remain a fair amount of scope of std to change. Although a lot of vendors associated to the technology have already launched products, based on the available specs(draft stage). The obvious reason is that no one expects a major change in standards. But yes, there would definitely a change, otherwise it would have already be finalized and closed without waiting for the 1st week of May

malc-barry0309
malc-barry0309

I have just installed my NEW Belkin Wireless N1 Router, it has taken me about 3 days because there is no software to install, the CD that comes with it only has a manual (pdf) so after a few headache's and swear words I have now got it working and it's very good and would recommend it, if you have the headache pils, but dont take my word for it, go and get one, it's the future. Malc

abhinav
abhinav

I think most of the people w.r.t. the 11n supported devices are very excited about the new technology and standards. And since the specs itself are not yet frozen, it is too early to comment much on it. Yes, the possible changes are inevitable, but I really do not think it will have any major impact on the current specs that we have in place. WiFi itself is aware of the facts and the extent of damage that could happen in case any major changes are done to the standards, esp at this point of time. Although there will be little cosmetic changes but definitely not major. And as the heading says, "............"; only the time will tell.

JaredH
JaredH

Working for the Educational market, I need something that is going to be compatible with multiple vendors! Until the 802.11n standard is ratified, I won't touch it. I will keep my 802.11g or switch to 802.11a before I go with any pre N deployment. The way I see it, we still have 6 months to a year before anyone can seriously look at 802.11n.

boomchuck1
boomchuck1

I purchased a Netgear pre (draft, whatever) N router on the promise of greater coverage. One issue is that you need pre n in your computer to get this kind of coverage and very few folks have got that. Since this was for a public area there was no advantage there. Second issue also had to do with coverage. The Netgear pre n actually didn't give me as much coverage as the Netgear WPN824 MIMO router. I spent $140 for the pre n and $40 (refurbished at Fry's) for the WPN824 MIMO. The MIMO router definitely gave superior coverage. Here's another issue of mine with going high speed on wireless... If you are passing data from one device to another then this higher speed does make a difference, but if all you're doing is providing wireless access to the Internet then what is the big deal? At home I have cable modem with a top speed of 4mbs or so. Doesn't matter if my wireless can talk 11mbs or 108mbs, I still can't get to Google any faster than the broadband allows. Give me coverage and signal strength any time.

ajlowson
ajlowson

We have used the Belkin Pre-N device and the firmware version 1000 works a treat so we when and purchased a couple more but these were with the fireware version 2000 and we can not get them to work, Belkin have no plans to update the fireware as yet and we are now looking into sending them back so beware of the new firmware 2000. hope this helps

Ollie J
Ollie J

I have the nextgear Rangemax Next router and the corresponding PC adapter, setup was easy, (took about 2-3 mins) and I get a (claimed) 300Mbps. The range covers my whole house, I upgraded because my G network coverage was not enough. I am very hapy with the new setup. I have been running it for about 6 months now and would recommend it for people who really need the range and/or speed of transfer (I move large files around a fair amount). Also, my laptop with a G card in it has no trouble connecting anywhere in the house too. Just my 2c worth.....

houchens
houchens

We switched about a year ago to a Belkin Pre-N router. The result was much stronger signal when used between upper and lower floors. Solved a big problem for us with Wireless.

jattas
jattas

I think George has it nailed, concerning interference and interoperability. The fact of the matter is that the FCC, has lost control once again of the airways, similar to when CB ran amok. This one will not be solved easy either. For those of you not familiar with it, they just dispensed with licensing of CB to solve the problem, and everyone went away but the truckers, who use it constantly. Now for the real problem. I install commercial wireless for Marina's and Yacht Clubs. In order to penetrate the fiberglass of these boats, we have to do two things: Increase the power by amplification (limited by FCC standards), and use relatively small antennas which cross polarize all signals and concentrate the signal further, so that penetration is possible. Guess what! These signals can be detected as much as 5 miles away! I am sure there are other applications of this which are very much the same. I used in one installation a cisco setup, with 1 watt power, that had a solid range of 13 miles with a dish up at 100 ft. Now the new bandwidth is going to destroy the number of channels being used at the present time, and certainly limit the future use of the airwaves as such. Questions?

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