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Thursday, January 17, 2008

Here's looking at you next generation WiFi



Things are hotting up in the South African broadband landscape. The list of commercially available technologies is growing rapidly and truly getting to grips with the intricacies of each technology is something most consumers are unlikely to be interested in. Quality of service is the bottom line. Can I get the service that I need at the right price? That is the question. It's also a question we are not going to answer, in the context hotspots powered by next generation WiFi, until the very end of this post.

WiFi is effectively a set of wireless LAN (local area network) standards called the IEEE 802.11 standards. The Institute of Electrical and Electronics Engineers (IEEE) is the body that does the standardisation and it is generally a lengthy process. The current WiFi standards are 802.11b and 802.11g with the latter offering higher data rates. The next generation of WiFi is 802.11n and it is not officially a standard yet not only due to standardisation being time consuming but also for various other reasons [1][2]. Even though it is not a standard yet, equipment manufacturers have begun making routers [3] that support the draft standard. The logo shown at the top of this post is what one should look for when buying such a router and the inclusion of the n with the word draft next to it means that the equipment has been certified, by the Wi-Fi Alliance, to be a router that is Wi-Fi Certified 802.11n draft 2.0 (click to get the official take on the meaning of the logo and term). The 802.11n standard is expected to be ratified by the IEEE by the end of this year.

Having touched on the status of 802.11n, lets jump straight to the key differentiators of 802.11n, what can it do for us all? The key advantages are:

  • Improved range - areas in a venue that would previously have had no or poor signal quality should have improved coverage when a certified 802.11n router is used as a drop in replacement for a 802.11b/g router
  • Improved performance - 802.11n offers higher data rates and speeds ranging from 100 - 200Mbps have been reported [3]. Multimedia applications, such as streaming video, require more bandwidth or "fatter pipes" and 802.11n delivers on these requirements. They not only require more bandwidth but also performance characteristics such as lower latency and 802.11n has the ability to deliver on this requirement.
Having mentioned that 802.11n offers improved range and performance, the next questions that come to mind are how much improvement is on offer and also, for the technically inclined, how is the improvement achieved?

To answer the first, with regards to range, a ball park figure is that 802.11n offers twice the range as 802.11b/g in the same environment. It is not possible to give a precise figure as every room or building is different, the material used in construction and other environmental aspects will affect the exact increase in range. The frequency used also effects the range but more on that later. From RedButton's perspective this is good news as it would make delivering on our commitment to providing signal coverage in all relevant areas of venues that much easier. With regards to bandwidth, one can expect roughly five times the throughput. This is certainly attractive when it comes to locally hosted services and activities such as streaming video on the local area network. At RedButton however we currently isolate clients from one another for security reasons and do not host any video services on our local area networks. That being said we still welcome the increase in throughput as at certain locations, where we have as many as 3 concurrent 4Mbps ADSL lines powering a single hotspot, clients would see improved performance when it comes to Internet access.

With regards to the technicalities behind 802.11n, we'll just touch on the key points, for in-dept , academic coverage, O'REILLY's 802.11 Wireless Networks is a good source. The key technical enhancements of 802.11n are:
  1. MIMO technology: This stands for "Multiple-in, Multiple-out" and involves the use of multiple antennas to send and receive more than one signal simultaneously.
  2. Effective use of multiple frequency bands: With 802.11b/g the 2.4GHz frequency band was used exclusively, with 802.11n both the 2.4GHz and the 5GHz frequency band are used [4]. The increases in performance offered by 802.11n have largely been seen when using the 5GHz band [3], not the 2.4GHz band.
We are quite excited about 802.11n and there is no doubt that we'll use it when most new laptops start shipping with 802.11n cards built in. This is only likely to happen once the 802.11n standard has been ratified by the IEEE and so only in the first or second quarter of 2009.

Can I get the service that I need at the right price?

Since the next generation WiFi, 802.11n, is only likely to start being widely adopted in 2009, the question is will I be able to get the service I need at the right price? When it comes to the service one needs, each person has different requirements but its a safe bet that each hotspot client wants good signal strength in all areas of a venue and an Internet that is as fast as possible. First of all, a 802.11n hotspot would still need to be powered by an Internet backbone (whether its WiMax, ADSL, satellite, iBurst, Neotel CDMA, metro Ethernet, the list goes on) and it's difficult to predict what prices will be like in 2009, we do know that they will drop. That being said with 802.11n from a hotspot operators perspective the capital expenditure at each hotspot is likely to be less as fewer routers would be required to provide the same coverage as with 802.11b/g routers. So in conclusion, we predict that you will be getting vastly superior service levels at significantly lower rates in 2009 and the deployment of 802.11n is likely to be a factor in price reductions.