Variant mimo with a single receiving antenna also known as the mode stc (Space Time Coding with space-time coding) and are particularly suitable in nlos conditions.

ААS - adaptive antenna systems: AAS uses multiple antennas to dynamically generate a directional beam. This beam is controlled by a base station (BS) for sending to a subscriber station (SS), and (BS) communicates. The AAS system is particularly suitable for use in scripts

with limited interference and can provide a significant benefit in an environment with direct visibility (LOS). System Iskratel default support for MIMO A/B & STC, AAS system will be added where it will be technically and commercially profitable.

Figure 21 - General view of the deployment of WiMAX technology in Egoryevsk area.

Solution SI3000 Light ASN provides simple network design and the use of "commodity" items (i.e., homogeneous elements, elements of mass production with the same properties) to establish a mobile connection to the network service provider. The result is a mechanism of handover and to continue the IP session, providing a handover in real-time for a fixed WiMAX network and handover carrier-class mobile WiMAX network. The SI3000 solution Light ASN also supports standard network elements outside of the ASN. In addition, the possible migration type SI3000 ASN - GW Mobile WiMAX. When the market and technology intersect, you'll be ready to offer full support for roaming and interoperability with a wide range of applications CSN.

Figure 22 - Physical connection to the WiMAX network.

Light from ASN Iskratel can offer:

- mobile services with much less infrastructure costs.

- SI3000 Light ASN - new network architecture

- In decision SI3000 Light ASN uses a new network architecture (New Network Architecture), which is a unique structure that allows you to use inexpensive and homogeneous (commoditized) network elements to create a managed, mobile, rich multimedia services networks.

New network architecture SI3000 Light ASN, based on a simple hierarchy configured with homogeneous (commodity) network elements, provides structure between the base network CSN and WiMAX radio network.

Figure 23 is a Logical connection to the WiMAX network.

The advantages of the new network architecture:

- Unique and innovative architecture;

- Deployment of homogeneous (commodity) elements (switch, router) with little cost;

- Sufficient WiMAX SS/SSM; no MobileIP stack for SSM;

- "Subversive" influence (disruptive impact);

- Ensures the mechanism of handover and to continue the IP session;

- Provides the ability to control QoS for Triple Play service delivery.

5. Development of a WiMAX NETWORK FOR the realization of BROADBAND ACCESS TO the INTERNET

5.1 Choice of the characteristics of the radio interface

Base station WiMAX is a modular solution which may, if necessary, be supplemented by the various units, for example, modules for connections to backbone network provider. In the minimal configuration is installed, the radio interface module and the connection module with a wired network.

When choosing WiMAX equipment in addition to its technical characteristics and the prices are important and often decisive importance is such a factor as to Russia's specific difficulties completing frequency permits. The fact is that in Russia there are practically no "unlicensed" bands. For different types of equipment provided different procedures for obtaining a frequency permits. To work in all ranges of the operators should get quite complex and multi-level resolution as frequency of services and services oversight communication [5].

It is obvious that in our country the chief factor affecting the speed of deployment of WiMAX systems, are the issues of regulation of the spectrum, since the development of WiMAX services market is directly dependent on the allocation of operators required frequency resource. Today the most perspective from the point of view of the future development of WiMAX technology are the ranges in the area of 2.4 and 3.5 and 5.6 GHz.

Note that the propagation of radio waves in different frequency bands has its own characteristics that largely determine the range of the equipment, as well as resistance to multipath.

Equipment must be performed by a specialized company with experience in the development and production of wireless equipment that is some guarantee of quality.

Technical characteristics of the equipment provided by the manufacturer, should be complete enough for you to make a conclusion about its capabilities. The representation of such characteristics speaks about the professionalism of the staff and to some extent ensures that we are talking about the original product and not about the resale of an unknown brand under the brand name of the seller.

It is desirable that the base station is able to centrirovannyi and gradual increase performance, for which she should be able to connect an external antenna. Then the first step one base station with omnidirectional antenna, the next two, the antennas with the width of the diagram 180°, and so on.

The equipment must be certified.

Must be able to obtain permission for the use of frequencies in the ranges used in the equipment.

The system must have acceptable cost, especially important minimum cost of subscriber equipment.

The principle of operation of Mobile WiMAX identical cellular networks: multiple adjacent base stations Mobile WiMAX form a honeycomb, honeycomb unites each other to ensure the continuous coverage of the whole city. Equipment Mobile WiMAX provides high speed data transmission, compared with cellular networks, and comparable to the speed of wired access networks. Key features WiMAX devices:

Technical characteristics of WiMax:

• Range: up to 50 km;

• Maximum data transfer rate: up to 70 Mbps per sector of one base station;

• Operating frequency: 2-11 GHz;

• Spectral efficiency: up to 5 bits/sec/Hz;

• Coverage: extended operation beyond line of sight greatly improve the quality of coverage of service area;

• Speed access to the Internet within a sector of the base station on the client devices - up to 10 Mbps;

• The coverage area of a single sector base stations in dense areas - from 800 to 1500 meters;

• Mobility: instantaneous switching client Mobile WiMAX equipment between the base stations at speed up to 120 km/h.

5.2 Calculation of frequency channels

The total number of frequency channels allocated to sweep the cellular network connection in a given location, determined by the formula

(10)

where int(x) is the integer part of the number x;

Fk - the frequency band occupied by a single frequency channel system (frequency separation between the channels).

5.3 determining the dimensionality of the cluster

To determine the required dimension of the cluster With given values of p0 and pt are used, the ratio

(11)

where p(C) - the percentage of time during which the ratio of signal power/ interference power at the receiver input of MS will be below the protective relationship .

The integral represents the tabulated Q-function:

. (12)

The lower side of the interval has the form:

, (13)

where and expressed in dB;

- is determined by the ratio

. (14)