Network communication technology paper 1 Communication technology will develop to network convergence technology.
abstract:
Wireless cellular network has developed from the first generation analog network to 4G(LTE and LTE-A) network, which has made brilliant achievements and played a great role in promoting social development. According to statistics, as of the second quarter of 201/kloc-0, the number of wireless users of various standards in the world has reached 5.7 billion, of which GSM is the most successful, with the number of users reaching 5 1 100 million; With the continuous development of data demand, 3G systems, including WCDMA and CDMA2000, and 4G systems represented by LTE are also developing gradually. In the foreseeable development period, various wireless standards will exist for a long time, which will promote the development of wireless communication.
1 traditional wireless communication technology encounters technology? Bottleneck?
Today, the evolution of each generation of communication technology is accompanied by the continuous development of basic technology. The corresponding basic technologies include signal propagation, coding and network architecture. In terms of signal propagation, 1G is analog technology, followed by digital technology after 2G; 2G multiple access technology includes time division (such as GSM) and code division (such as CDMA), 3G is wideband code division, 4C is LTE represented by orthogonal frequency division multiplexing (OFDM). The development of each generation of technology aims at improving spectrum efficiency, expanding available bandwidth and increasing speed to meet the ever-developing communication needs of users.
However, the traditional wireless communication technology has been gradually satisfied today? Bottleneck? . The maximum capacity of spectrum efficiency of traditional wireless communication depends on Shannon theory, and the improvement of spectrum efficiency by various technologies has gradually approached Shannon limit. As shown in figure 1. Under the traditional theory, it is relatively difficult to further improve the spectrum efficiency, so the development of new technologies seems to be in trouble.
In recent years, LTE-A mentioned in the communication industry refers to more antennas (MIMO), higher bandwidth, inter-cell cooperation and so on. , also can't see the new technological development. For the technical choice of 5G, there seems to be no better choice than quantum communication. However, quantum communication is still immature. Quantum communication has been developed since 1990s, and it has been transmitted over a long distance in some experimental cases, but it may take 5 ~ 10 years or even longer to be applied to practical industries. Of course, under any circumstances, don't think that the development of technology will stagnate. In the19th century, no scientist thought the classical theory was perfect. In the future, scientists will only do experiments to verify previous theories. However, at the beginning of the 20th century, new theories, such as relativity and quantum theory, opened a new chapter in human science and technology, and promoted human beings to make great scientific and technological progress in the 20th century. Similarly, what happened to traditional communication technology? Bottleneck? It does not mean that communication is no longer developing, but indicates that communication technology may face some greater breakthroughs.
2 Multi-network convergence is the focus of future development
Encountered in the development of basic technology? Bottleneck? Under the new circumstances, multi-network integration has become one of the key points to promote technological development. 2G, 3G, 4G and Wi-Fi networks will exist for a long time in 5 ~ 10 years. Real networks have gradually formed heterogeneous networks with various wireless standards and coverage (such as macro, micro and micro coverage), as shown in Figure 2.
Under the existing heterogeneous network architecture, it will become an important task for network deployment to fully integrate various wireless technologies, maximize all existing network capabilities, maximize the overall network capabilities, and provide users with the best services.
From the deployment stage, multi-network convergence will present several stages:
(1) different network construction stages
Focus on the impact of the new network on the original network, such as wireless interference, site storage, etc.
(2) * * * storage stage based on coverage
The new network is generally based on the original network, and the coverage of the new network is difficult to ensure continuity and comprehensiveness. Coverage-based network storage has become the focus of ensuring the customer experience of wireless networks. Figure 3 shows the partial coverage of LTE in 3G and 2G coverage areas. When the coverage of LTE network is insufficient, the function of redirecting to 3G network or switching to 3G network becomes an important means to ensure the customer experience. The same demand is also reflected in the process of indoor Wi-Fi construction.
(3) Multi-network collaborative integration stage
Core network and access network will be further integrated and developed. Converged networks allocate data streams according to different network loads, service types and user types to achieve the best overall effect. The multi-network cooperative fusion network is shown in Figure 4.
Network convergence will be realized at three levels: core network, access network and terminal.
(1) The core network realizes unified authentication and unified access of various wireless data.
By controlling the Integrated Service Gateway (ISCW), the core network can realize the dynamic allocation of resources based on service types, users and network loads, optimize the utilization of various network resources, and provide users with quality services. The dynamic resource allocation architecture based on service type, users and network load is shown in Figure 5.
(2)RNC, BSC, eNodeB and AC are used as access anchors for coordinated control.
With wireless centralized control nodes such as base station controller, radio network controller (BSC/RNC) and access controller (AC) as anchor points, control is carried out at base station level or regional level, and joint radio resource control (JRCM) is carried out according to cell load, access restriction, wireless interference, terminal capacity and user moving speed, so as to provide users with the best user experience. Joint radio resource control is shown in fig. 6.
(3) Interference control ensures the existence of various wireless technologies.
Spectrum is one of the basic resources of wireless technology, and making full use of all kinds of effective spectrum is the focus of wireless development. The utilization of spectrum includes the utilization of existing blank spectrum and the spectrum reorganization of the original spectrum, as shown in Figure 7. During the construction of 1800 MHzWCDMA and LTE, the spectrum reorganization of adjacent frequency and original GSM spectrum was included. With the development of wireless access technology. The spectrum is more fully utilized, and the interference control between adjacent frequency bands becomes the basis to ensure the existence of various wireless technologies. Interference control includes isolation of wireless access devices in adjacent frequency bands, interference suppression of * * * mode devices and interference solutions. Accordingly, technologies such as self-organizing network (sON) and inter-cell interference coordination (ICIC) will gradually play their important roles.
(4) The terminal supports multi-access and realizes multi-mode simultaneous operation.
Future terminals will adapt to the development of multi-network convergence and support multi-mode simultaneous operation, that is, multiple access bearer (MAB). With the development of technology, multi-band wireless interference, broadband antenna, power consumption and other technical obstacles. , which limits the multimode capability of the current terminal, will be gradually solved, and the terminal supporting MAB will become the focus of future development.
4 Wi-Fi will play an important role in multi-network construction.
As a low-cost indoor coverage technology, Wi-Fi as a data distribution method has been adopted by many operators. Wi-Fi works in a public frequency band, and the price of its network equipment is less than 1/5 of that of general wireless cellular base station equipment. Because of its low investment and quick effect, it is favored by operators. In the current WLAN construction, the interference of Wi-Fi and the channel quality affect the customer experience to some extent, and also limit the wide application of WLAN. However, with the increasing use of WLAN as a wireless access method by operators, the above problems will be gradually solved. With the enhancement of interoperability with other access modes, WLAN will become a very important indoor wireless access mode, and will build a high-quality data network together with LTE, 3G and other networks.
5 concluding remarks
The long-term existence and development of 2G, 3G, 4G and WLAN determines that network convergence technology will become an important technology for network development. Realizing the coordinated development of various wireless networks at multiple levels, fully developing data services and providing users with more convenient, reliable and high-quality services will be the focus of wireless technology development in the next few years.
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