【正文】 s xrays taken locally.4)Telegeoprocessing applications:The bination of geographical information systems (GIS),global positioning systems (GPS), and highcapacity wireless mobile systems will enable a new type of application referred to as dependent on location information of several users, in addition to temporal aspects have many applications.5) Crisismanagement applications:Natural disasters can affect the entire munications infrastructure is in munications quickly is wideband wireless mobile munications Internet and video services, could be set up in hours instead of days or even weeks required for restoration of wireline munications.6) Education :Educational opportunities available on the internet, for individuals interested in lifelong education, will be unavailable to client in remote areas because of the economic unfeasibility of providing wideband wireline internet wireless munications provides a costeffective alternative in these situations.VII. ROLE OF THE WIRELESS INDUSTRY RECOMMENDATIONSWe are bringing to the attention of professionals following issues and problems that must be analyzed and resolved:1)Standardization: Standardization of wireless networks in terms of modulation techniques, switching schemes and roaming is an absolute necessity for 4G. We must pay more attention to general meaning advanced technologies.2) Lower Price Points Only Slightly Higher than Alternatives: The business visionaries should do some economic modeling before they start 4G hype. They should understand that 4G data applications like streaming video must pete with very low cost wireline applications.3) More Coordination Among Spectrum Regulators Around the World: We must demand almost free spectrum NOT necessarily unlicensed Spectrum regulation bodies must get involved in guiding the researchers by indicating which frequency band might be used for 4G.4) Regulatory frameworks: Policy and Regulatory Environment which Provides Transparency, Certainty and a Level Playing Field are necessary. The most important thing is that we should recognize that regulatory framework is as much an evolving matter as technology, and be prepared to meet changes with an openminded and pragmatic attitude, always keeping the interests of the industry and consumers in mind.5) More Academic Research: Universities must spend more effort in solving fundamental problems in radio munications (especially multiband and wideband radios, intelligent antennas and signal processing).6) Voiceindependent Business Justification Thinking: Business and Technology executives should not bias their business models by using voice channels as economic determinant for data applications. Voice has a builtin demand limit data applications do not.7) Integration Across Different Network Topologies: Network architects must base their architecture on hybrid network concepts that integrates wireless wide area net works, wireless LANS (IEEE , IEEE ,IEEE , IEEE and IEEE ), Bluetooth with fiberbased Internet backbone. Broadband wireless networks must be a part of this integrated network architecture.8) Nondisruptive Implementation: Upgrading from 3G to 4G is expected to be seamless to endusers with no device upgrades required.VIII. DEVELOPMENTS IN 4GATamp。D (distribution)—refers to the distribution of signals, which may consist of simultaneous voice, data, Internet, and video traffic。s home directory server on the home network forwards this to the careof address via a tunnel, as in regular mobile IP. However, the directory server also sends a message to the puter informing it of the correct careof address, so future packets can be sent should enable TCP sessions and HTTP downloads to be maintained as users move between different types of of the many addresses and the multiple layers of subnetting, IPv6 is needed for this type of mobility.V. TECHNOLOGIES THAT SUPPORT 4GThe revolution in 4G will be the optical networking, the new air interface, the portable device etc.A. The Transmission Protocols1) OFDM: OFDM is a digital modulation technology in which in one time symbol waveform, thousands of orthogonal waves are is good for high bandwidth digital data transition.2) WOFDM: WOFDM enables data to be encoded on multiple highspeed radio frequencies concurrently. This allows for greater security, increased amounts of data being sent, and the industry’s most efficient use of enables the implementation of low power multipoint RF networks that minimize interference with adjacent enables independent channels to operate within the same band allowing multipoint networks and pointtopoint backbone systems to be overlaid in the same frequency band.3) MCCDMA : MCCDMA is actually OFDM with a CDMA to singlecarrier CDMA systems,the users are multiplexed with orthogonal codes to distinguish users in (multicarrier) in MCCDMA, each user can be allocated several codes,where the data is spread in time or frequency.4) LASCDMA：Link Air Communications is developer of LASCDMA (Large Area Synchronized Code Division Multiple Access) a patented 4G wireless technology. LASCDMA enables highspeed data and increases voice capacity and latest innovative solution, CDD, merges the highly spectral efficient LASCDMA technology with the superior data transmission characteristics of resulting bination makes CDD the most spectrally efficient, highcapacity duplexing system available today.B. The Radio InterfaceUWB RadioTo make 4G really work carries will need to migrate to Ultra Wideband (UWB) radio will deliver essential new wireless and wired bandwidth inexpensively, without using precious and scarce radio ,digital video, voice and data are enabled using modulated pulses of energy that peacefully coexist alongside traditional radio solves the multipath fading issues and is 1,000% more process efficient than CDMA.C. The NetworkLMDSLocal multipoint distribut