A consortium of companies is pushing a new proposal to the IEEE for 802.11n. 135 Mbps in standard mode, 540 Mbps maximum throughput. Fast enough?
A consortium of companies calling themselves the WWiSE group, for "World Wide Spectrum Efficiency," has put forward their own proposal to the IEEE 802.11n working group, which is working on the next generation of Wi-Fi, claiming to scale from 135 Mbps all the way up to 540 Mbps. The WWiSE group consists of Airgo Networks, Bermai, Broadcom, Conexant, STMicroelectronics and Texas Instruments.
The IEEE's working group for 802.11n requires all proposals to exceed 100 Mbps transfer speed, making them faster than even conventional wired Ethernet. (Gigabit Ethernet is available, but not widely used outside of server rooms and network carriers.) Agere Systems made one proposal for 802.11n earlier this summer that the WWiSE group doesn't like, so they are making their own proposal.
More importantly, the WWiSE group has agreed that, if their proposal is accepted, member companies would license any patents they hold that are necessary to implement the proposal royalty-free to anyone who asks, although such licenses would be revocable if the licensee and WWiSE member got into a court fight later on. Royalty-free licenses for standards are important, as they reduce the cost of entry and encourage additional companies to produce products based on the standard. That in turn increases competition and drives down prices, which is always a win for end users. Most of the most important standards that underpin the Internet are not only royalty-free but license free as well, such as TCP/IP, HTTP, the Domain Name System, and the various protocols that make up the e-mail system.
The WWiSE proposal for 802.11n is very similar to the Agere Systems proposal in terms of functionality. Both are based on MIMO-OFDM techniques. MIMO stands for Multiple Input-Multiple Output, which in non-engineering terms means that both sending and receiving devices require multiple antennas, specifically two in this case. OFDM stands for Orthogonal Frequency Division Multiplexing, and is a more complex but more efficient and higher-bandwidth way of letting multiple radio transmissions share the same airspace and frequency at the same time than Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA), both widely used by mobile phone networks.
Both the WWiSE and Agere Systems proposals support up to 135 Mbps transfer rates with two antennas on both sender and receiver, and claim backward compatibility with conventional Wi-Fi technologies. By adding additional antennas up to a 4x4 configuration (four senders, for receivers) WWiSE claims that their proposal will scale to 540 Mbps. However, that will require using a 40 MHz-wide band. Current regulatory requirements limit 2.4 GHz-band transmissions to a 20 MHz slice of frequency in most jurisdictions.
The IEEE (Institute of Electrical and Electronics Engineers) is responsible for developing and maintaining a wide variety of networking specifications and standards important to the basic functioning of the Internet, including, among others, wired Ethernet and wireless Ethernet "Wi-Fi". Current Wi-Fi standards include 802.11b running at 11 Mbps and 802.11a and 802.11g, both of which run at 54 Mbps, although 802.11g was originally developed independently by Texas Instruments. 802.11b and 802.11g operate in the unlicensed 2.4 GHz frequency band, as does the WWiSE group's 802.11n proposal, while 802.11a operates in the unlicensed 5.4 GHz band.