Why the rush? In November 2002, Broadcom made a hugely successful gamble by releasing the first 802.11g chip set several months before that standard was officially approved. Although the company had no market share at the time, Broadcom held its position against later 802.11g competitors and ultimately became the leading vendor of Wi-Fi chips. This time, companies such as Atheros, Conexant, Marvell, and Realtek will not give Broadcom such an easy victory. These vendors and others have already prepared near-final chip designs, guessing at what will be in the 802.11n draft standard. When the draft is complete, the race will be on to make a few final tweaks and deliver to customers. Path to a Standard A group called TGn has been developing the 802.11n standard since September 2003. The goal of 802.11n is a maximum throughıput—not raw data rate—exceeding 100Mbps. This throughput represents at least four times the performance of the original 802.11a/g standards and is large enough to support multiple streams of high-definition video. The 802.11n standard will support 2.4GHz and 5GHz operation and will include modes that are backward compatible with 802.11a and/or 802.11g. Many competing proposals for a draft standard were presented at the September 2004 meeting of TGn. Most major chip vendors supported one of two consolidated proposals, known as TGn Sync and WWiSE. Unfortunately, neither proposal earned the required 75% membership approval. To avoid a stalemate, the TGn Sync and WWiSE groups met in June 2005 to begin developing a single merged proposal. A confirmation vote on the merged proposal is scheduled for November 2005. This vote should be the starting gun for vendors to produce 802.11n chip sets; assuming the proposal is confirmed as scheduled, the first sample chips should appear in 1Q06. Because ratification of the final standard is unlikely before 2007, these early products will not be marketed as 802.11n-compliant. Although these chips will all implement the same draft standard, the vendors may use different terms to describe them, and interoperability will not be guaranteed. These early vendors run the risk that the standard will change before it is finally approved. A large installed base of products based on the draft standard, however, will put tremendous pressure on the TGn group to ratify the draft standard without modification. Any changes are likely to be optional or apply only in special situations. Pre-N Products Lead the Way A few vendors have already jumped the gun to introduce proprietary chips that implement technologies that will be part of the 802.11n standard. For example, Airgo Networks offers a chip set that adds MIMO (multiple-input multiple-output) technology to the existing 802.11a/g standards. Using multiple antennas to both transmit and receive radio signals, Airgo’s “True MIMO” chip set can double the speed of 802.11a/g, achieving a 108Mbps raw data rate. Airgo has been shipping MIMO products for two years and now holds about 5% of the overall 802.11 market revenue. Because of their premium performance, Airgo’s chips sell for two or three times the price of commodity 802.11a/g chips. Airgo’s chips will not be compatible with the 802.11n standard, however, and deliver only half of the 802.11n performance target. The company plans to use its MIMO expertise to quickly develop products for the 802.11n draft standard. Atheros, the second-largest Wi-Fi chip vendor, doubles the effective data rate of its newest chip sets using channel bonding. By combining two standard 20MHz channels, Atheros achieves a result similar to the 40MHz channels proposed for 802.11n. Atheros also uses a two-antenna design to improve range, but it does not implement spatial multiplexing, a critical MIMO technology. The company plans to add MIMO features and deliver a product that complies with the draft 802.11n standard. Airgo and Atheros have proved that end users will pay extra for greater performance and longer range, paving the way for high-speed 802.11n products that enable wireless video distribution throughout a home. We expect sales of 802.11n products to grow quickly, boosted by earlier products based on the draft standard. The race is about to begin, and leadership of the Wi-Fi market is at stake.
|
