10.5. Mobile communications of the 21st century.

Prospective markets can be viewed in the context of the capabilities and limitations of 3rd generation mobile systems, which are summarized at the level of the UMTS and IMT-2000 concepts. Scenarios for the development of mobile communication markets are determined mainly by the already developed technologies of communication and information processing, the introduction of which on a large scale will take place over the next ten years, that is, until 2015.

Target installations of 3G networks are formulated by many experts in specific technical criteria, for example as follows:

- mobile multimedia services for all users at the level of today's prices for fixed telephony;

- high-speed access services to Internet resources using personal mobile terminals operating with a capacity of up to 2 Mbit / s;

- global mobile communications available in mass markets for 15 ... 20% of the total population of the Earth, that is, for a total subscriber base of 1 ... 1.2 billion people in most countries of the world.

The question of 21st-century mobile communications is already beginning to be discussed by experts in the context of 4th-generation 4GW wireless network infrastructures. Projects of 4GW networks are defined for the perspective of 15 ... 25 next years, that is, at the level of development of mobile communications until 2025.

Naturally, now we are not talking about the development of specific technical projects and technological standards, but about possible scenarios for the development of future communications and those megatrends that need to be carefully monitored when developing strategic decisions and directions for future research and development. At present, there are no accurate forecast methods and reliable analytical studies that allow to give a complete picture of the state of future mobile communication in 15-25 years. You can only talk about the use of common methods of scenario modeling, that is, the construction of fairly plausible scenarios for the development of 4th generation mobile networks. The following basic ideas can serve as the methodological basis for building such scenarios.

A. Development scenarios based on defining changes of a global nature.

For example, at the Royal Institute of Technology (Stockholm, Sweden) three basic 4GW scenarios are being developed: a) the “Anything Goes — Everything is Moving” scenario; b) the scenario "Pocket Computing - Pocket Computing"; c) The Integrity scenario. The basis for the construction of these three scenarios is the method of processing expert estimates of probable dates of occurrence of key events such as: “In which year all household electronic devices will be equipped with adapters for local radio communications” or “In which year all cars will have built-in global positioning and radio communications systems”.

B. Development scenarios based on an analysis of the mobile services market and the business interests of the main operating forces in world markets.

In 1995, Ericsson undertook a multi-year study called “2005 - Ericsson Entering the 21st Century” (Ericsson enters the 21st century). The purpose of such research is to identify the most important for a particular company market sectors and potential positions that are most beneficial for the company in these markets.

B. Development scenarios based on an analysis of future network infrastructures that meet targeted performance and efficiency criteria.

An example of this approach is a brainstorming study conducted in November 1998 under the auspices of the National Science Foundation NFS (USA) on the problem of building wireless networks with a TK capacity of 44.736 Mbit / s. The results of this study are summarized in [10.7].

Potential applications for 4G networks.

In the NFS study, the concept of 4G mobile networks is defined in accordance with the general scheme, in which movement from 2G and further to 4G is considered with an increase in the transmission rate from 0.01 to 100 Mbit / s. The main performance indicator of 4G networks is determined according to the classification of digital communication lines used in the United States by the National Institute of Standards (ANSI) for evaluating trunk lines and communication networks. There are four classes of digital communication lines: T1 - 1,544 Mbit / s, T2 - 3,152 Mbit / s, TZ - 44,736 Mbit / s, T4 - 274,760 Mbit / s.

Standard digital TOR lines correspond in their performance to 672 voice communication channels, each of which provides a transmission speed of 64 kbit / s over one channel, that is, the TZ line is equivalent to 672 V-ISDN channels. Achievement of TZ in the wireless communication channel means that such a channel will provide broadband digital communication, high-speed multimedia transmission, integration with fixed-line communication networks ISDN, implementation of advanced communication protocols such as ATM, SDH, MPEG, etc.

In tab. 10.6 shows the comparative characteristics of four generations of mobile communication.

The “performance” line indicates the maximum data transfer rates achieved in stationary or low-mobile applications. As follows from this table, the transition to the next generation requires an increase in channel performance by about 15-20 times. Channel performance is a basic communication parameter that determines other network characteristics: QoS communication quality, connection setup time, message latency, multimedia data parameters.

High-performance channels of mobile communications TZ allow implementing a number of new classes of applications that are essential for 4th generation networks. These new applications include the following NFS research.

Virtual navigation - mobile subscribers have online access to geographic databases (information on urban areas, streets, buildings and other objects).

Telemedicine - mobile access to databases of medical records, radiographs, toxicological data, etc. Videoconferencing and multimedia information services can also be used.

TV information - a combination of mobile communications, access services to geographic information systems (GIS) and global positioning systems (GPS). Such applications can be used in exploration, environmental studies, monitoring of agricultural harvests.

Crisis and emergency management - rapid deployment of mobile networks in conditions of extensive catastrophes, accidents of extended power grids, rescue operations, etc.

Educational networks in sparsely populated areas - wireless access to educational databases, multimedia e-mail, video conferencing and other applications in conditions of an underdeveloped and unreliable telephone network.

Multimedia group communications - providing project teams, repair and construction teams, surgical teams, mobile video call-in services and access to multimedia information. Members of the group in the solution of common tasks can be in motion, at a great distance from each other and use different broadcast, group and targeted communication modes.

Rapidly deployable local mobile networks — consumer electronics home networks, mobile medical laboratories, fieldwork networks for agricultural work, etc.

For TZ class applications, the main modes are: transfer of large files in real time, support for high-speed video data streams, interactive access to Web servers, adaptation and reconfiguration of various radio interface parameters of mobile terminals.

Research Needed to Build 4G Networks

As part of the NFS study, the main areas of research for future mobile communication systems are identified. The following areas are highlighted:

- models of physical radio channels for broadband;

- intelligent adaptive antennas;

- separation of channel resources between different types of traffic;

- mechanisms of interaction and optimization of joint work of system components;

- Handover procedures for high-speed subscriber data streams;

- adaptation and application configuration mechanisms for changing channel conditions;

- dynamic allocation of resources;

- joint procedures for coding input and channel information streams. Research issues were discussed in five focus groups:

1) physical channels;

2) signal processing;

3) mobile and network protocols;

4) system-wide architectures and protocols;

5) applications and services.

For example, the following directions for the study of mobile applications in the network environment class TK:

- data caching and database replication (optimization of the distribution of application data in dynamic communication modes, for example, data caching in a mobile terminal during a communication session);

- adaptive broadcasting modes using subscriber profiles and multicast network protocols;

- transaction management (transaction recovery, modeling, transaction authorization);

- adaptive methods of using software components (including optimization of database queries);

- methods for ensuring data protection;

- information access architecture with regard to broadband TZ channels (client-server models, client-agent-server models, filters);

- methods of error handling and recovery, taking into account the increased probability of failures and errors in broadband high-speed channels;

- methods for processing dynamic geo-information (indexing of geocontexts, geosynchronous languages, fuzzy search criteria);

- organization of data and applications sensitive to subscriber contexts (location, speed and direction of movement of the subscriber).

Network infrastructure 4G networks.

4G network infrastructures will be built on the basis of high-speed backbone and subscriber communication lines. However, the defining direction of the development of network infrastructures will not be a transition to more powerful transport mechanisms, but a deep structural restructuring of networks. Network infrastructures will evolve under the influence of the following major trends.

Globalization of products, services and corporations. Globalization is already taking place today on the basis of the development of international trade, the introduction of new forms of electronic business and the networked Internet economy, and the expansion of the scale of production of goods and services. Mobile network infrastructures are gradually transformed into global “data pipelines”, which will be facilitated by the creation of “Internet in the sky” networks based on broadband satellite communication technologies.

Mass distribution of wireless consumer electronic devices. Practically all household appliances, measuring devices, sensors, portable computers, biomedical sensors, video cameras, electromechanical mechanisms for various purposes, and other devices will be equipped with built-in microprocessors and radio communication systems. Wearable computers and personal wireless networks will be universally used by many people in their daily lives. The network hierarchy of structural components will allow building communication networks of various dimensions based on universal interworking protocols.

Separation of network infrastructures into independent levels according to functional principles. Network infrastructures of various scale and purpose will be increasingly divided into separate functional levels: servers and service providers, transport and gateway mechanisms, call management and quality of service. Standardizing inter-layer interfaces will allow telecom operators and service providers to reach new levels of network specialization and interworking.

The emergence of new functional elements in network infrastructures. The increasing importance of information and multimedia content in network services, the increasing personalization of communication services, the growing diversity of Web services will gradually lead to the emergence of new infrastructure elements (network nodes and specialized subnets). These elements include: information brokers, semantic filters for the selection of high-quality or narrowly targeted data streams, multimedia gateways and large media media buffer drives, localization servers for servicing queries on the coordinates of mobile subscribers and vehicles.

IP aggregation of subnets and infrastructure elements. Radio transmission technologies in cellular networks, multimedia data exchange between various network nodes, subscriber services and network processes are gradually being upgraded based on IP protocols. In network infrastructures, new gateway nodes appear that perform the functions of aggregating IP subnets. Packet switching becomes a universal network technology that implements a wide range of performance parameters and internetwork connectivity of various types of networks (fixed, wireless, subscriber radio access, etc.).

Multimode access points. Different access points (base stations, gateways, IP ports) will evolve towards supporting multiple radio interfaces and connecting a wide range of terminals and electronic devices for various purposes. The cost of these access points will be significantly reduced, which will ensure the ubiquitous distribution of multi-mode "radio sockets" for wireless connection of terminals and organization of local networks. Adaptive self-tuning antennas will be used by mobile operators for serving subscribers and interworking with mobile local networks.

Terminals A variety of subscriber devices and electronic devices with interfaces will increase by several dozen times compared to 3G terminals. The range of traffic speed parameters will also significantly expand: from 10 kbps for simple instruments and sensors up to 100 Mbps for multimedia personal computers. The terminals will be able to use the new frequency bands 5 and 60 GHz. To operate at high frequencies, the terminals will be equipped with adaptive antennas.

New radio frequency resources. Telecom operators will be provided with new broadband radio resources in both licensed and unlicensed bands. The 5, 20, 40 and 60 GHz bands will play an important role in many applications: high-speed data transmission, satellite communications, interactive television, telemetry data collection, cellular broadcasting, scientific and medical measurements. Methods for sharing the radio spectrum by operators will be developed.

A brief examination of the infrastructural tendencies outlined above allows us to conclude that there are large or possibly radical changes in network structures during the transition to the 4G mobile communications generation. It is clear that when it comes to long-term processes, it is most important to take into account the macro trends and developmental characteristics that define common targets.