In recent years, the wireless access technology of broadband demonstrates the unprecedented prosperity with innovating in technical research and development, 802 serial standards of IEEE are fast growing, 802.11, 802.16,etc. technology nowadays becomes the focus that the industry of wireless communication pays close attention to.
IEEE802.16 standard and associated research work
IEEE802.16 standard also called WirelessMAN aerial interface standard, mainly applies the range to Wireless MAN. 802.16d (namely 802.16-2004) It is the interface standard in the sky of the FWA, and 802.16e moves the broadband wireless access standard. 802.16d corresponds to 10GHz- 66GHz and frequency domain smaller than 11GHz, can carry on the viewing distance and transmission that is not the viewing distance. 802.16e operating frequency is smaller than 6GHz, supports the speed to move, the coverage is several kilometers, can offer the speed of 15Mbps on 5MHz signal channel.
802.16d and 802.16e have just defined the physical layer of air interface, MAC layer, has not involved upper strata network and application. In order to promote the development of industry, WIMAX is launching network architecture standard and business and employing the demand etc. at present.
IEEE802.16 is a canonial formulator of the technology, WIMAX is the pushers of technology and industry chain, WiMAX makes important contributions to IEEE conformance standard, with the development of 802.16 canonicalization, WiMAX is advancing the test job of conformance progressively too.
It is tetherless access work groups WG3 that CCSATC5 is divided into that China is engaged in the standard tracing and research of broadband wireless access. WG3 has already finished the associated research report of 802.16 technology at present, the relevant technical standard has been already in making too.
IEEE802.16 technical application and market prospect
802.16d can support 10GHz- frequency bands of line-of-sight propagtion in frequency band and 11GHz in line-of-sight propagtion of 66GHz. According to the propagation characteristic of different frequency bands, its application is different to some extent too. As to the line-of-sight propagtion frequency band of 10GHz- 66GHz, because terminal needs the outdoor antenna, its application is mainly to offer the transmission over radio of Backhaul for small and medium-sized enterprises. As to the thing that that under 11GHz is not the frequency band of line-of-sight propagtion, because can realize the indoor is covered, its application will be mainly concentrated on offering the data traffic of broadband to personal user. In addition, 802.16 can also realize the rear end transmission function of enterprise Wi-Fi hot areas, and LAN interconnection, data individual line, narrow-band service and base station interconnection,etc..
Compared with other mobile communiation systems, 802.16e system has higher spectral utilization factor and transmission rate, therefore it is suitable for offering and surfing the Net with broadband and moving video business.
With answer and start with piece (for instance xDSL, Cable, optic fibre are inserted) while being wired while being other Compare, 802.16 broadband wireless access has disposing speeds more quickly, higherrer advantage of the stronger, flexibility of expanding ability. It is lower to population density and easy to lay the area of xDSL, can offer " wireless DSL " by 802.16 Serve, range that face family and small enterprise application. In the building of medium-sized scale enterprises, 802.16 can support the high speed to connect, insert instead of the optic fibre.
802.16e technology and 3G technical comparison
Generally speaking, in wireless transmission technology, 802.16e has sacrificed the excursive improvement which has gained the transmitting capacity of the data, the bandwidth of its data is superior to 3G system. From network connection, compared with 3G system 802.16e is not ripe enough, the associated standard also needs further improving, so that can support the mobile service better in the future.
In business, 802.16e is directed primarily to having certain excursive business of networking of broadband, and defined the complete QoS system. The business characteristic on the basis of the speech, video, data,etc. has defined 4 kinds of types of traffic in 802.16e standard, correspond to different the intersection of QoS and rank separately, carry on allocation of resources of difference, offer the assurance at various degrees for different business. In 3G system, speech and packet data of the core network are separated, adopt the way of basedding on circuit switching as to the speech, and have high QoS guarantee. As to the packet data traffic, WCDMA has defined more complete QoS mechanism, but not directed against the business systematic QoS in CDMA2000. In sum, 802.16 technology has very good potentiality of market, as to operator of China, 802.16 can help the wired operator which insert resources to enter the market of broadband rapidly as a kind of new connecting starting with section. But unify multi-angles such as frequency spectrum, techincal characteristics,etc. to consider since canonicalization, commercial time, the whole world, really commercial distance that is sure of 802.16e distance. In future technical development, many kinds of wireless technology will coexist for a long time, each other is complementary to compete also, give play to one's own advantage its respectively, meet different users and the application's demands.
