The Future s So Bright

The Future's So Bright…

Rather than spending too much time imagining the future, we will get on with the task of understanding today's WLAN standards. Even though researchers are busy pushing back the wireless frontier, it's not likely that products using their breakthroughs will be available for a while, whereas the existing IEEE 802.11 standards are already quite a lot to wrap our minds around, are important today, and are likely to remain important for a rather long time to come. Despite the long evolutionary road ahead of WLAN standards, the current generation will probably have a long half-life, and an understanding of how these standards operate should be very useful to end users and administrators alike.

What about Faster Speeds?

Many IEEE 802.11a vendors already have proprietary (non-interoperable) methods to achieve twice the bandwidth of IEEE 802.11a; in other words, 108 Mbps. This sounds great on paper, but few such products ever get more than 40 Mbps throughput in real environments.

The progress of WLAN standards so far has been in multiples of 5, as can be seen in Figure 3-21. If that trend holds, we can expect to see 250 Mbps WLAN products in a few years. Despite the shockingly high bandwidth, such speeds are actually within reach of modern Digital Signal Processors, although products supporting the extremely high-order modulations will be expensive to produce for some time, and their peak speeds will only be reached under ideal operating conditions; however, it is certain that speeds of well over 200 Mbps should be achievable, and even practical, within 5 years.

Figure 3-21. Evolution of top speeds of IEEE 802.11 PHYs

In an effort to bring interoperability to the >50 Mbps speed regime, the IEEE 802.11 WG has begun work to form the High Throughput Task Group, to begin in September 2003 and be known as IEEE 802.11n, to define WLAN standards that should offer a minimum of 100 Mbps throughput.

It is clear that despite its success so far, WLAN technology is still in its infancy. This observation is not meant to diminish the accomplishments to date of the IEEE 802.11 WG, the Wi-Fi Alliance, or of the hundreds of vendors who have built and marketed IEEE 802.11-compliant products, but just to remind everyone that there is a lot of room for improvement in WLAN technology. There is no doubt that wireless is the future, and that the future has already begun.