Accessing information anywhere, anytime, with a seamless connection to a wide range of information and services, and receiving a large volume of information, data, pictures, video, and so on, are the keys of the 4G infrastructures. The future 4G infrastructures will consist of a set of various networks using IP (Internet protocol) as a common protocol so that users are in control because they will be able to choose every application and environment. Based on the developing trends of mobile communication, 4G will have broader bandwidth, higher data rate, and smoother and quicker handoff and will focus on ensuring seamless service across a multitude of wireless systems and networks.
Application adaptability and being highly dynamic are the main features of 4G services of interest to users. These features mean services can be delivered and be available to the personal preference of different users and support the users traffic, air interfaces, radio environment, and quality of service. Connection with the network applications can be transferred into various forms and levels correctly and efficiently. The dominant methods of access to this pool of information will be the mobile telephone, PDA, and laptop to seamlessly access the voice communication, high‐speed information services, and entertainment broadcast services. The Fourth generation will encompass all systems from various networks, public to private; operator driven broadband networks to personal areas; and ad hoc networks.
The 4G systems will interoperate with 2G and 3G systems, as well as with digital (broadband) broadcasting systems. In addition, 4G systems will be fully IP‐based wireless Internet. This all-encompassing integrated perspective shows the broad range of systems that the fourth generation intends to integrate, from satellite broadband to high altitude platform to cellular 3G and 3G systems to WLL (wireless local loop) and FWA (fixed wireless access) to WLAN (Wireless local area network) and PAN (personal area network),all with IP as the integrating mechanism. With 4G, a range of new services and models will be available. These services and models need to be further examined for their interface with the design of 4G systems.
IMPLEMENTATION USING 4G
The goal of 4G is to replace the current core mobile networks with a single worldwide core network standard, based on IP for control, video, packet data, and voice. This will provide uniform video, voice, and data services to the mobile host, based entirely on IP.
IP is assumed to act as an adhesive for providing global connectivity and mobility among networks. An all IP‐based 4G wireless network has inherent advantages over its predecessors. It is compatible with, and independent of the underlying radio access technology. An IP wireless network replaces the old Signalling System 7 (SS7) telecommunications protocol, which is considered massively redundant. This is because SS7 signal transmission consumes a larger part of network bandwidth even when there is no signalling traffic for the simple reason that it uses a call setup mechanism to reserve bandwidth, rather time/frequency slots in the radio waves. IP networks, on the other hand, are connectionless and use the slots only when they have data to send. Hence there is optimum usage of the available bandwidth. Today, wireless communications are heavily biased toward voice, even though studies indicate that growth in wireless data traffic is rising exponentially relative to demand for voice traffic. Because an all IP core layer is easily scalable, it is ideally suited to meet this challenge. The goal is a merged data/voice/multimedia network.
Multiplexing (SDM)—information signals are multiplexed on spatially separated N multiple antennas and received on M antennas. Figure shows a general block diagram of a MIMO system. Multiple antennas at both the transmitter and the receiver provide essentially multiple channels that operate simultaneously on the same frequency band and at the same time. This results in high spectral efficiencies in a rich scattering environment (high multi‐path), since you can transmit multiple data streams or signals over the channel simultaneously.
With the hype of 3G wireless in the rear view mirror, but the reality of truly mobile broadband data seemingly too far in the future to be visible yet on the information super highway, it may seem premature to offer a test drive 4G. But the good news is, 4G is finally coming to a showroom near you. There are sweeping changes taking place in transportation and intelligent highways, generally
referred to as “Intelligent Transportation Systems” (ITS). IT is comprised of a number of technologies, including information processing, communications, control, and electronics. Using these technologies with our transportation systems, and allowing first responders access to them, will help prevent or certainly mitigate future disasters. Communications, and the cooperation and collaboration it affords, is a key element of any effective disaster response. Historically, this has been done with bulky handheld radios that provide only voice to a team in a common sector. And this architecture is still cellular, with a singular point of failure, because all transmissions to a given cell must pass through that one cell. If the cell tower is destroyed in the disaster, traditional wireless service is eliminated. 4G wireless eliminates this spoke‐and‐hub weakness of cellular architectures because the destruction of a single node does not disable the network. Instead of a user being dependent on a cell tower, that user can hop through other users in dynamic, self-roaming, self‐healing rings. This is reason enough to make this technology available to first responders. But there is more: mobility, streaming audio and video, high‐speed internet, real time asset awareness, geo‐location, and in‐building rescue support. All this at speeds that rival cable modems and DSL. Combining 4G with ITS infrastructure makes both more robust. In 4G architectures, the network improves as the number of users’ increases. It offers the network lots of users, and therefore more robustness. Think of every light pole on a highway as a network element, a “user” that is acting as a router/repeater for first responders traveling on those highways. Think of every traffic light as a network element, ideally situated in the centre of intersections with a 360‐degree view of traffic. This is the power of the marriage between 4G networks and ITS
4G provide with a very efficient and reliable wireless communication system for seamless roaming over various network including internet which uses IP network.