Since 802.11n is the next generation of WLAN standards, it must have some advantages over former standards. While in the notebook market today, there are already some 802.11n product like routers and netcards being utlized. So, in my point of view it will lead a revolutionary change in both the equipments and the wireless network throughput all over the world. For example, analyst firm ABI Research forecasts that 802.11n chipset shipments will increase from 93 million units in 2007 to about 1.1 billion units in 2012, dominating overall Wi-Fi shipments of 1.2 billion units.This considerable rate of growth reflects the fact that 802.11n promotes expansion of Wi-Fi into new market segments and applications in the home and in the enterprise. From different environment the poisitive aspect of 802.11n will be different. But there is one rule will not change, that is improvment!
With its increased coverage and throughput, 802.11n enables HD video and audio-visual (AV) multimedia applications in the home environment. Increased throughput and WMM capabilities enable more reliable transport of simultaneous voice and multimedia sessions.WMM certification helps ensure high quality of Wi-Fi calls, while the increased throughput and coverage of 802.11n provides sufficient bandwidth to transport multiple video streams to Wi-Fi enabled set-top boxes or TV sets around the house.
The high bandwidth and QoS of Wi-Fi CERTIFIED 802.11n draft 2.0 systems helps ensure that an internet connection can be reliably shared by the increasing number and type of Wi-Fi enabled devices in the home without degradation of service. Higher data rates of 802.11n also increase the throughput capacity of overlapping Wi-Fi networks.The increased range of 802.11n provides coverage of the entire house, reaching farther than the legacy technology and reducing “dead spots” or low-rate areas in the home. Even single-antenna mobile devices, such as Wi-Fi phones, will enjoy the benefits of increased range and throughput of Wi-Fi CERTIFIED 802.11n by virtue of the transmit diversity capabilities, such as Space Time Block Coding (STBC), Cyclic Shift Diversity (CSD) and Transmit Beamforming.Most network transactions, including voice and data services, will benefit significantly from the 802.11n frame aggregation technology. Printing files from PCs to printers, transferring files between PCs and network drives and sharing files between PCs, laptops and other devices on the network becomes more efficient with 802.11n thanks to frame aggregation.
802.11n is enterprise-grade technology that will provide IT managers with nearly the same reliable service they have come to expect from their Ethernet networks. Mission-critical enterprise applications, such as Customer Relationship Management (CRM) and Enterprise Resource Planning (ERP) access, collaboration tools, voice and video conferencing, will all benefit from the increased throughput and range of 802.11n.The new efficiencies and enhancements of 802.11n on the MAC and PHY layers, combined with the WMM QoS capabilities, serve to improve the quality of VoIP and to increase the number of simultaneous calls on the airlink. Physical layer transmission enhancements of 802.11n, such as Space Time Block Coding (STBC), improve reception even for single receiver Wi-Fi phones by virtue of transmitting multiple copies of a data stream via multiple antennas. Multiple versions of the signal reaching the phone are received and processed with specialized decoding techniques to provide redundancy of signaling and optimize reception.Of significant benefit to the Enterprise is lower density of APs, made possible by the improved efficiencies in the MAC, enhancements in the PHY operation and longer reach. Due to faster physical layer transmissions, stations get on and off the air faster, improving the airlink efficiency. The MAC layer mechanisms such as block ACK and frame aggregation also improve the airlink efficiency by reducing the overhead of packet headers, inter-frame gaps and ACK transmissions.Legacy stations in the 802.11n network can benefit from better coverage provided by the 802.11n APs’ CSD and MRC techniques and they can also gain increased access to the airlink as the new 802.11n devices get on and off the air faster.
Campus and Municipal Networks
Campus and municipal networks typically operate in challenging environments where range is the biggest issue. 802.11n is well-equipped to improve the operating range even for single-antenna handheld devices used in such outdoors networks. Increased range of handheld devices is achieved through AP transmit and receive diversity mechanisms. Transmit diversity of APs, including STBC and transmit Beamforming, improves the downlink range performance. Receive diversity of APs, including MRC, reciprocate the transmit diversity and thus maintain the range for both the uplink and the downlink directions.
Improvements in Voice Performance
The handheld devices operating in the enterprise, campus and municipal networks enjoy improvements in VoIP performance and efficiency through protocols like, block ACK and frame aggregation. The required WMM part of the certification ensures that voice streams get priority over other classes of traffic and thus further enhances the voice service.