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BARS modules for wireless communication network.

Against the background of the rapid development of information and computer technologies, the spread of local and global data transmission networks, the issue of organizing a connection between a subscriber (computer or LAN) and the nearest node of the global network is an acute problem of the "last mile". One of the ways to solve it is to use radio access.

When they talk about the "last mile", they mean a distance from several hundred meters to 20-30 kilometers. In conditions where it is impossible or economically impractical to lay a cable or use point-to-point radio relay or radio modem equipment , the problem of the "last mile" can be effectively solved using a common high-speed wireless channel of the "point-to-many points" type, which is shared by several subscribers, as in a local Ethernet network.

This solution, called Radio-Ethernet, is standardized by an international committee IEEE is numbered 802.11 and can be implemented using any of the following technologies:

  • transmission in the infrared spectrum;
  • broadband signal transmission direct Sequence Method (DSSS);
  • broadband signal transmission by the method of frequency jumps (FHSS).

Broadband technologies (DSSS and FHSS) operating in the 2400-2483.5 MHz band have become widespread in Russia. Among the Radio-Ethernet equipment of various manufacturers widely represented on the market, CiscoAironet 350/340 Series manufactured by Cisco and Orinoco PC Card manufactured by Lucent, using DSSS technology, and BreezeNET PRO and BreezeACCESS II manufactured by Alvarion, working on FHSS technology.

The needs of gas and oil workers

Wireless technologies are especially relevant for oil and gas companies that need telephone communication and a data transmission network at remote drilling sites, as well as a digital communication channel between the work management and drilling sites scattered over tens of kilometers.

The main oil and gas production works are carried out in the north, northeast and south In Russia, in severe climatic conditions: permafrost, frosts up to -60SHC or, conversely, heat with temperatures up to +60SHC. At the same time, the drilling rig usually moves 50-100m after 1-3 months. In such conditions , it is impractical to use a multi-core cable for organizing communication channels , since it will have to be periodically re-laid, connected and configured equipment. Radio communication in the HF and VHF bands is used as the main communication on the drilling site.

The module of the base station of the radio communication "BARS"

Race Communications specialists have developed a module of the BARS radio base station, which uses BreezeACCESS II wireless access equipment. This equipment is designed for high-speed data and voice transmission over the radio channel and is an alternative to traditional solutions based on wired infrastructure, including ISDN, ADSL, or cable modems. It uses FHSS technology, which provides a data transfer rate in the radio channel of 3 Mbit/s and a guaranteed data transfer rate for the subscriber, which made it possible to implement Voice over IP.

Unfortunately, the operating temperature range of this equipment (-40 to +50SHC) does not allow it to be used in severe climatic conditions, and therefore an all-weather unified module of the BARS radio base station was developed , which ensures the operation of BreezeACCESS II radio equipment at ambient temperatures up to +60 SHC.

BARS modules provide communication and data transmission services to a platform within a radius of 3-5 km (depending on the antennas used), as well as trunk communication channels (speeds up to 3 Mbit/s) with stations located at other facilities. The module can also work in repeater mode - with a distance between neighboring modules up to 20-25 km.

BARS is designed for installation on sites that are difficult to access, such as drilling rigs, roofs of buildings and other high-rise structures. Its design is such that the installation can be carried out by unskilled personnel for a minimum time.

The BARS module functions autonomously (only a power cable is connected to it ), the design allows it to be adapted to any operating conditions and placement options on the site. The monitoring system and automatic maintenance of the parameters of the internal environment of the module at any ambient temperature provide additional reliability. The tools necessary for initial diagnostics and troubleshooting in case of module failure , a tester and a lighting lamp are included in the delivery package.

Currently , the model range of "BARS " includes four modules:

  • BARS-1M10 - for connecting the terminal node,
  • BARS-1M15 - for connecting a node with by retransmission,
  • BARS-2M10 - for connecting the terminal node (has controls for state and mode of operation),
  • BARS-2M15 - for connecting a node with by retransmission (has means of control for the state and mode of operation).

BARS-1M10 and BARS-2M10 work as a terminal station that receives a signal from the base station of the network and distributes it around for several kilometers. BARS-1M15 and BARS-2M 15 act as repeaters, receiving a signal from the base station of the network, spreading it around for several kilometers and transmitting it to the next module at a distance of up to 20-25 km.

The BARS module can also be used in urban wireless communication networks:

  • as a repeater - if the base city wireless network PD station according to their energy indicators or due to the interference of urban development, it "does not reach " subscribers;
  • to connect to the group's urban network subscribers 20-25 km away;
  • for quick deployment wireless PD network in a limited area up to 3-5 km;
  • in the interests of banking structures - for wireless connection of cash registers terminals and ATMs.

Features of the BARS modules

  • Lack of strict placement requirements. It can be installed on high-altitude hard-to-reach sites. The possibility of mounting the module on the site by unskilled personnel. Easy installation and rewiring when moving (only the module is connected to power supply cable).
  • Effective use radio frequency resource.
  • Ability to organize channels data transmission with guaranteed performance.
  • The ability to transfer data and fixed-line telephone organization communications. Performance of the created networks that ensure efficient operation complex software systems and the transmission of the necessary telemetry information.
  • The ability to connect to an institutional telephone network or trunking communication system via the central node of the data transmission network.
  • Ability to configure and manage equipment from a single center.
  • The ability to use the module as a repeater for the organization connections with other modules.

Alexey Zubkov, Head of the Design Department of Race Communications.

Source: World of Communication. CONNECT. No. 03/2002, pp. 120-121

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