Inmarsat satellite communications. Satellite mobile communication systems. Globalstar Mobile Satellite Communications System

INMARSAT system

ERA-Service LLC- official agent representing interests CJSC MVS Global Telecommunications", official representative FSUE Morsvyazsputnik, which is an operator / provider of communication services in the Inmarsat system according to all standards and in all oceanic regions; international settlement organization SU04 on the basis of License No. 5274 of the Ministry of Communications of the Russian Federation.
Within the framework of the concluded agreement ERA-Service LLC provides two-way 24/7 communication services (telephone, fax, telex, data transmission) in the global automatic international mobile system satellite communications Inmarsat, and also provides payments for communication services in the Inmarsat system and international ship radio traffic.

The international company Inmarsat (headquartered in London) was originally created to ensure the safety of navigation. Over the years, Inmarsat communications have found numerous users on land and in the air, especially in regions where traditional communications are unreliable or non-existent.
Having retained the original status of an international organization, Inmarsat in April 1999. became a private limited company (Inmarsat Ltd.) registered in the UK.
The new international company Inmarsat is also based in London and is governed by a trusted Board of 13 directors.

Inmarsat has more than 170,000 users, served by approximately 200 system service providers in more than 80 countries. Inmarsat also has other partners, including equipment manufacturers, suppliers software products, system integrators (systems engineering enterprises) and enterprises selling services and equipment. Inmarsat is in an exceptional position, having licenses to operate the system in 171 countries. This provision appeared back in 1979. Inmarsat became a pioneer in the development and creation of a global satellite communications system. With more than 20 years of experience behind it, Inmarsat currently operates four generations of its own geostationary satellites.
Technically, the Inmarsat system consists of an orbital constellation of satellites located in geostationary orbit, a network of earth stations (coast earth stations) and user terminals. The call from the subscriber terminal arrives via satellite to the BZ, which then routes it to the appropriate terrestrial network. IN reverse direction a call from a subscriber arrives at the BZ, which routes it to the terminal. Thus, all connection establishment functions are performed by the base station; satellites are used only for signal relay.

Network management.

Traffic through Inmarsat satellites is monitored and managed by a Network Operations Center (NOC) located at Inmarsat headquarters in London. NOC operation is supported by Network Coordination Stations (NCS). The main task of NCS is to allocate channels to the base station and the terminal for establishing a connection. There is one NCS for each ocean region and standard (A, B, C, etc.). All NCS constantly exchange operational information among themselves and with the NOC.

User terminals.

User terminals are divided into several large groups, so-called standards. Terminals of each standard have the same set of services provided. Here a brief description of existing standards:

• Standard A is the very first type of Inmarsat terminal. Provides voice and telex transmission over an analog channel. It can also provide high-speed data transfer (64Kbps). Currently, terminals of this standard are not produced. Inmarsat plans to stop supporting them.
• Standard B is a digital version of Standard A, providing voice, fax (2.4 Kbit/s), low-speed data transmission (2.4 Kbit/s), telex, HSD). Available in ship, land and vehicle versions.
• Standard M is a portable version of Standard B, the first Inmarsat terminal to be housed in a case the size and appearance of an ordinary briefcase. Provides voice, fax (2.4 Kbps) and data (2.4 Kbps). Currently being replaced by Mini-M and M4 (GAN) terminals.
• The Mini-M standard is a smaller and cheaper version of the M standard. It provides the same services as the M standard, but has the dimensions of an average laptop.
• The GAN(M4) standard is an extended version of Mini-M. Originally called MultiMedia Mikni-M, hence M4. With the same dimensions, it additionally provides ISDN (64/56 KBit/s) and MPDS mode. MPDS is a mode specially designed to provide economical and comfortable Internet browsing. When communicating in MPDS mode, payment is charged for the amount of information transmitted/received, and not for the connection time, as in other cases. The data transfer rate in MPDS mode is not guaranteed, but can reach 64 Kbps.
• Fleet is a marine version of GAN. It comes in three versions, differing in functionality (and price). The most functional is F77, then F55 and F33.

• SWIFT is an aviation version of GAN.

• Standard C - provides the exchange of text messages both between terminals and with various terrestrial data networks - X25, Internet, X400. In the marine version it can be equipped with a built-in GPS receiver. It features small dimensions of the antenna and interface unit. In the Mini-C version, the interface unit is combined with the antenna while maintaining its dimensions.

• Standard D and D+ - global pager. D+ is distinguished by the ability to send short messages.

Inmarsat satellites.

The satellites are located at four points above the equator, each of them serving its own part of the earth's surface, the so-called ocean region. There are 4 ocean regions:

• Atlantic-East (AOR-E), the satellite is located at 15.5°W.
• Atlantic-West (AOR-W), the satellite is located at 54° W.
• Pacific (POR), satellite located at 178° East.
• Indian (IOR), satellite located at 64°E.

Each of the ocean regions has its own international dialing codes used for calls in the terminal-to-terminal and shore-to-terminal directions in telex mode:

• Atlantic East (AOR-E): 581
• Atlantic-West (AOR-W): telephone - 874, telex - 584
• Pacific (POR): telephone - 872, telex - 582
• Indian (IOR): telephone - 873, telex - 583

For telephony, since 01/01/2009, a single code 870 has been used, denoting “all satellite regions”. The previously used ocean area dialing codes (871,872,873,874) have been officially returned by the ITU.
The Inmarsat satellite control center is located in London, the tracking and telemetry collection stations are in Canada, China and Italy.

Inmarsat operates three generations of satellites: Inmarsat-I2, I3 and I4. The Inmarsat I2 satellites were built by British Aerospace (now BAE Systems), launched in 1990-1992 and had a design life of 10 years. Currently, the I2-F3 satellite is decommissioned, I2-F1, F2 and F4 are used as backup for the Pacific, Western Atlantic and Indian regions, and are also leased.
The Inmarsat I3 satellites were built by Lockheed Martin Astro Space (now Lockheed Martin Missiles & Space), which was responsible for the spacecraft, and European Matra Marconi Space (now Astrium), which developed the communications equipment. The satellites were launched in 1996-98. A total of 5 satellites were launched. The I3 satellites introduced the concept of zonal beams - each of them is capable of generating a global and up to seven zonal beams. Thanks to the use of zonal beams, it became possible to develop more compact user terminals, such as Inmarsat-M and Mini-M.
The I4 satellites are the latest addition to the Inmarsat satellite constellation. Two of the planned three satellites have been launched. The I4 satellites are the basis of Inmarsat's new broadband network. Each of the I4 satellites has more capacity than the three I3 satellites. Compared to the previous generation, the power has been increased by 60 times, the efficiency of spectrum use has been increased by 12 times, and the sensitivity of receivers has been increased by 25 times.

Like its predecessors, the I4s have a global beam covering 1/3 of the earth's surface and 19 wide zonal beams covering the same area and supporting the latest Inmarsat terminals, such as Fleet F77 128K, Fleet F55, Fleet F33. There are also 228 narrow area beams that support the BGAN network. BGAN terminals have data transfer rates of up to 492 kBit/s.

INMARSAT BGAN system

BGAN system is the first in the world to be publicly available mobile network communications, providing simultaneous voice communication and high-speed data transmission from almost any point on land using one portable device. It is also the first network of its kind to offer guaranteed on-demand connection speeds. The data transfer rate in the BGAN network can reach 500 Kbps.
So, when working in remote locations, you can use the same services and applications as in the office.

BGAN uses the power of Inmarsat 4th generation satellites - I4. Currently, 3 satellites are in use - I4 Americas (put into operation on 01/07/2009, located at 98°W), I4 EMEA (will be located at 25°E, put into operation after repositioning on 02/02/2009) and I4 Asia-Pacific (currently located at 64°E, after repositioning (from 02/06/2009 to 02/24/2009) will be located at 143.5°E. Thus, after the completion of the transfer of I4 satellites to new orbital positions (according to the plan, all operations should be completed on February 24, 2009) the Inmarsat BGAN system will become the first commercially available global system broadband satellite communications.
For communication, the L-band is used: from 1.5 to 1.6 GHz. The channel occupies a 200 kHz band.
The BGAN network consists of user terminals, relay satellites in geostationary orbit and a ground complex. The terrestrial complex includes base stations located in Fucino (Italy) and Burum (Netherlands), as well as a gateway for connecting to terrestrial networks. Unlike previous Inmarsat standards, the ground equipment is owned by Inmarsat and not by its partners. Both BZS are connected to each other and to the gateway via high-speed data transmission channels.
The following figures show communication schemes for individual and group subscribers:

• Standard IP Services

Variable Bit Rate (VBR) Data Transmission
-IP background class data transmission (as defined by 3G industry standards)
-Maximum channel speed up to 492 Kbps for transmission and reception

• IP Streaming Services

Guaranteed bit rate service
-Availability upon request
-QoS with streaming class (as defined by 3G industry standards)
-32, 64, 128, 256 Kbps for transmission and reception

• Voice communication

4Kbps circuit-switched voice services
-Calls are made using an external handset or headset (some terminals can connect via Bluetooth)
-Voice mail
-Additional services: call waiting, call barring, call holding, forwarding

64 kBit/s
-Unlimited/limited data streams (UDI/RDI)
-Digital and analogue mode
-Support is implemented on certain types of terminals

SMS exchange between BGAN terminals
-Supports the ability to exchange SMS with terrestrial networks cellular communication

The BGAN terminal is controlled using a standard software interface, common for all types of terminals - BGAN LaunchPad. BGAN LaunchPad exists in versions for Windows 2000, XP, MacOS 9.2, 10.1, Linux RedHat 9.
Main properties of BGAN LaunchPad:

• Easy to use
• Step-by-step navigation instructions satellite terminal and connection setup
• Possibility of individual configuration of data transfer parameters depending on the specific application
• Preset user access settings, for example to limit access to streaming data
• Online access to credentials and billing system information
• Personal and corporate versions
• Access to text messaging (SMS) and phone services

Lecture No. 30

Inmarsat satellite mobile communications system

The international organization Inmarsat was founded in 1979. The purpose of the organization was to provide communications to sea vessels and improve the safety of maritime transport. Since then, Inmarsat has become the only (until recently) provider of mobile satellite communications services. For a long time now, its services have been used not only by sailors, but by everyone who may need fast and high-quality communications. Initially, the abbreviation Inmarsat stood for International Maritime Satellite Organization (International Maritime Satellite Organization). satellite organization), after the organization entered markets not related to maritime transport, it, without changing the abbreviation, changed its name - International Mobile Satellite Organization (International Mobile Satellite Organization). The organization is funded by the 84 countries that are its members. Soviet Union(in the past) and Russia (in the present) are represented in Inmarsat by the state organization Morsvyazsputnik.

Before launching its own satellites, Inmarsat used leased capacities on satellites of other communication systems: two Marisat satellites (operator - Comsat General, USA), two Mareks satellites (operator - European Space Agency), capacities on Intelsat fifth series satellites. Since 1997, the organization has completely switched to using its own satellite capacities.

Currently, the space segment of the system consists of four second-generation Inmarsat-2 satellites and five third-generation Inmarsat-3 satellites.

Each third-generation Inmarsat satellite, in addition to the global beam, forms five narrow beams (spot beam), allowing the use of terminals of smaller size and power.

Management and control spacecraft is carried out from the Satellite Control Center located in London and from tracking, telemetry and command stations located in Fucino (Italy), Beijing (China), Lake Cowichan (British Columbia) and Pennant Point (Nova Scotia).

The Inmar-sat satellite communication system is ready to provide its user throughout the entire Earth, excluding the polar regions, with telephone and telex communication, fax transmission, data transmission, email. The system can also provide determination of object coordinates, transmission of flight status reports from the aircraft, transmission of dispatch information from an aviation or automobile terminal, automatic reading and transmission of data, and transmission of a distress signal.

Analog marine terminal equipped with an antenna with a diameter of 1 m. Allows two-way telephone communication, fax transmission and data transmission at a speed of 9.6 kbit/s. As of January 1998, more than 25 thousand Inmarsat-A terminals were sold.

It is a digital analogue of the Inmarsat-A terminal. In addition to telephone and fax communications, it allows data transmission at a speed of 64 kbit/s or 56 kbit/s. The Inmarsat-B HSD terminal (high-speed modification) provides video signal transmission, conference calls, and operation via TCP/IP protocols. More than 5 thousand terminals have been sold (as of January 1998).

Cheap option. Provides two-way store-and-forward data transfer at 600 bps. Weight electronic module- 3-4 kg. About 39 thousand terminals were sold (as of January 1998).

Small terminal for one-way data transfer.

Two-way data transfer. Determining the location of an object using GPS systems. These terminals are used to transmit stock exchange information, control road freight transport, and also as emergency beacons.

This terminal is used to determine the geographic coordinates of an object and, if necessary, issue a distress signal.

Figure 88 Inmarsat-M devices

Mobile terminal (briefcase size for portable land mobile option). Provides digital telephone (4.8 kbps), data (2.4 kbps) and fax (2.4 kbps). Produced in automotive and marine versions. The antenna is equipped with a tracking and gyrostabilization system.

Inmarsatphone (Mini-M)

Since January 1996, after the first third generation Inmarsat satellite was launched, the operation of the Inmarsat Mini-M terminal has become possible. This terminal was designed specifically to operate in the narrow beam of Inmarsat 3 satellites.

Inmarsat Mini-M provides digital telephone communication (4.8 kbit/s), data transmission (2.4 kbit/s), fax communication (2.4 kbit/s). The mobile version is the size of a laptop computer. There are marine, automotive and stationary options.

Depending on the dealer, the cost of the terminal ranges from 3 to 4 thousand dollars, with separate payment for connection and license. Thus, the cost of the minimum initial package will be about 4.5 thousand dollars. Call time is billed at $3 per minute, including VAT. About 18 thousand terminals were sold (January 1998).

Figure 89 Inmarsat coverage areas and earth station locations

Figure 90

The terminal is designed for use on aircraft. It is used for communication between the crew and dispatch services, automatic transmission of data on the state of the flight and aircraft systems, determines coordinates and calculates the most advantageous route, in the case of, for example, a flight over the ocean. It is also possible to provide passenger services - telephone communication, fax transmission, packet data transmission at a speed of 10.5 kBit/s, continuous data transmission at a speed of 4.8 kBit/s.

This terminal, similar to the Inmarsat Mini-M, was designed for operation in the narrow beam of third-generation satellites. The use of a narrow, more powerful beam made it possible to create a more portable terminal. Inmarsat Aero-I provides approximately the same capabilities as Inmarsat Aero - telephone communications, dispatch and flight information, packet data transmission at speeds from 600 bps to 4.8 kbps. The terminal provides all these capabilities only in a narrow beam; only one function is included in the global beam - sending a distress signal.

Allows data transmission at a speed of 600 bps and dispatch control over the state of the aircraft systems and its location.

Allows telephone communication and data transmission at a speed of 10.5 kbit/s.

Inmarsat Aero-C

Airplane version of the Inmarsat-C terminal. Performs batch text transmission and distress signal.

More than 1,500 aircraft are equipped with Inmarsat-Aero terminals. Of these, 500 are corporate and government, 1000 are commercial. More than 850 aircraft and helicopters are equipped with Inmarsat Aero-C terminals.

All Inmarsat terminals can now be interfaced with the GPS (Global Positoning System) satellite system and most national and international systems control over sea, road and rail transportation.

The signal received from the terminal is transmitted from the satellite to the earth station, from where it is switched in the public network. Earth stations, which are sometimes called shore stations (for sailors) or ground stations (for pilots), are the property of individual independent telecom operators. Often, but not always, the operator of the ES is a Participant - an organization nominated by its government to invest in the system and work with the Inmarsat organization - from the country in which the ES is located. A single AP can support many service providers.

The disadvantages and advantages have been discussed more than once low orbit systems before geostationary systems. In short: due to the greater distance, geostationary systems require greater power of user terminals; geostationary systems do not provide communications north of 70°N. and south of 70° S, however, the geostationary system can provide more traffic with fewer satellites and cover a much larger area of ​​the Earth's surface. Nevertheless, it is obvious that the commissioning of Iridium, GlobalStar and similar systems will greatly complicate the position of Inmarsat, which is still essentially a monopolist of mobile satellite communications. It would be strange if the board of the organization did not understand this. It is therefore not surprising that the Inmarsat Organization is the largest shareholder in ICO Global Communications. The company was founded in 1995 to develop and operate a medium-orbit global satellite mobile communications system designed to operate cellular-size handsets.

The system will operate 12 satellites (10 operational and 2 reserve in orbit) at an altitude of 10 thousand kilometers in two planes of intermediate circular orbits located at 45° to the equator. The system is expected to be operational by 2000 and will provide dual-mode phone service that can operate with existing cellular systems and via satellites.

This year, two satellite communications operators, which are intergovernmental organizations, decided to privatize. One of them is the International Organization of Satellite Communications Intelsat, the largest satellite operator, the second is the International Organization of Mobile Satellite Communications Inmarsat. Representatives of both organizations explain this step by the need to be more flexible in responding to market changes and consumer demands. It is possible that the development of the satellite industry has reached the point where cumbersome interstate organizations do not have time to properly respond to the emergence of new factors and changing conditions.

The decision to privatize Inmarsat was made on September 24, 1998 at the Assembly of Governments - Members of Inmarsat, held in Greece. Inmarsat, which is currently an internationally owned cooperative, will be converted into a limited liability company. The organization will acquire this status on January 1, 1999.

In accordance with the decision of the Assembly, the new structure will consist of two units: a limited liability company, which will issue shares within two years from its creation, and an intergovernmental body responsible for fulfilling Inmarsat's public responsibilities, including the Global maritime communications for Distress and Safety (GMDSS). The new company will be managed by a Board of Directors consisting of 15 members.

On this occasion, Inmarsat CEO Warren Grace said: “Inmarsat is the first intergovernmental organization to be converted into a private company. Inmarsat will be the vehicle for major investments in the next generation of satellites, able to be more flexible in meeting customer needs in a globally competitive environment.”

To date, a business project has been prepared for the launch and operation of three geostationary satellites fourth generation. The project was called "Horizons". The decision to launch fourth-generation satellites will be made by the Inmarsat Board of Directors after the company is restructured in 1999. The Horizons system satellites will allow the company to use terminals weighing less than one kilogram for high-speed data transmission up to 144 Kps, as well as for voice and video telephony, access to email and databases.

So, it can be assumed with a high degree of probability that, despite the emergence of low-orbit satellite systems, no one is going to abandon traditional geostationary ones. It can hardly be expected that new geostationary satellite mobile communication systems will appear, especially international ones (we repeat that there are quite a lot of national systems operating national satellite systems or international operators, such as, for example, Intelsat). However, there is no doubt that Inmarsat will play a leading role in this area. As always, the reader (or rather the consumer) has the right to choose.

Global satellite communications system Inmarsat (INMARSAT). Satellite-GSM phone IsatPhone

Figure 91

IsatPhone - new dual-mode mobile satellite phone, designed to work in the Inmarsat system.

For most people who travel the world or work in remote areas, the ability to make a telephone call is the number one requirement they place on their telecommunications systems. If previously users of the global satellite communications system Inmarsat had to put up with bulky and heavy terminals, now their main requirement is fully satisfied by the new dual-mode GSM satellite phone IsatPhone.

Key Features

Small size and weight

Easy to use

Modern design

Dual mode - satellite and GSM (GSM 900 only)

Talk time up to 3 hours

Wide range of available accessories

IsatPhone is one of the smallest and lightest satellite phones sold on the market. It is perfect for business people, tourists and all other categories of users who are going to travel to an area where other methods of communication with the outside world are unstable or impossible at all.

As standard, the phone is equipped with an external rotating antenna, a charger, a cable for connecting to a computer, a headset and a fairly thin battery.

Specifications

Dimensions: 130 x 50 x 32 mm

Weight: 210 grams (with battery)

Antenna: dual beam satellite and GSM rotating antenna

Operating time - talk: up to 2 hours 40 minutes (satellite and GSM modes)

Operating time - standby: up to 42 hours (satellite and GSM modes)

Data transmission/fax: up to 2400bps (satellite mode), up to 9600bps (GSM)

Volume notebook: 99 numbers per phone + SIM

Supported Services

SMS text (only in GSM mode)

Call hold

Conference calling with the ability to simultaneously connect up to 5 subscribers

Call forwarding and blocked, blacklist

Available accessories

Charger IsatPhone charger and cable

Adapters for various types sockets (for European, American and English)

Software GSM modem with USB connector, supports data transfer at speeds up to 9600 bps

Holder for IsatPhone

Indoor kit

Auto kit

Mobile satellite internet

This service allows you to provide all types of communications (telephone, Internet, fax, e-mail, video conferencing, etc.) to mobile users: geologists, military, cartographers, shepherds, hunters, fishermen, travelers and other users who do not have a wired mobile communications and Internet access.

System operation diagram

Figure 92 Inmarsat BGAN portable system

Inmarsat BGAN (Broadband Global Area Network) - portable two-way systems satellite Internet. The operation of the BGAN network is based on the use of Inmarsat - 4 series satellites, covering more than 90% of the earth's surface. A special feature of the BGAN network is the ability to simultaneously transmit data and voice.

The Inmarsat BGAN service is aimed primarily at frequently moving users who constantly need broadband Internet access. In addition, residents of remote regions deprived of other mobile means of communication can use the system.

Figure 93

The EXPLORER™ 500 subscriber terminal from Thrane&Thrane allows you to talk on the phone via satellite, provides high-speed Internet access and supports all types of communication (fax, e-mail, video conference). The terminal has LAN, RJ11, Bluetooth, USB interfaces. It is possible for several users to work simultaneously using different interfaces.

Setting up the satellite is simple and is carried out using the built-in compass and signal indicator and does not require special equipment. Equipment prices.

Reception speed - up to 460 Kbps, transmission - up to 128 Kbps Power: AC 220V, DC 12V (car), built-in battery (up to 1.5 hours in 144 Kbps transfer mode or up to 36 hours in standby mode) .

Dimensions: 217x217x52 mm, weight: about 1.5 kg.

Marine systems Inmarsat Fleet communications

Inmarsat Fleet maritime communication systems from KVH include more than a dozen types, but in Russian conditions it is realistic to use the Fleet 77 and Fleet 55 systems. Both systems are designed to provide users with fast Internet/Intranet connections, video conferencing, and global voice/fax services. Equipment prices.

Inmarsat Fleet systems allow users to work using the ISDN (Integrated Services Digital Network) and MPDS (Mobile Packet Data Service) protocols.

The ISDN protocol with per-minute billing is designed for high-quality voice and fax communications, video conferencing, and transfer of large files.

The MPDS protocol with per-megabyte pricing is designed for the “always online” state - the time spent on the network is not taken into account.

Inmarsat Fleet is fully compatible with ship communications systems and can act (when connected to an IP router) as a hub for the entire ship communications equipment complex.

Data download speed (ISDN and MPDS protocols): 64 Kbps, using proprietary software- up to 320 Kbps.

Power supply: 21 – 34 VDC current (15 A max.)

Antenna weight with radome: 26 kg (F77), 18 kg (F55)

Transceiver weight: 2.6 kg

Regional broadband satellite communication system Inmarsat RBGAN (INMARSAT Regional BGAN). Inmarsat RBGAN satellite modem.

Inmarsat RBGAN - system information

Specifications Inmarsat RBGAN terminal

Inmarsat RBGAN coverage area

Technical characteristics of the user terminal

Data transfer rate: up to 144 kbps

Work only if you have a SIM card

Built-in GPS receiver (for technological purposes without displaying coordinates)

Supports the following interfaces for connecting equipment: USB, Ethernet, Bluetooth

Indication of power on/off, battery status, received signal level, active interface (USB/Ethernet/Bluetooth) using LEDs

Supply voltage: 7.2 - 8.4 VDC

Weight: 1.6 kg (weight of the terminal itself)

Dimensions: like a laptop-class computer, 23 cm x 30 cm x 4.3 cm

Basic equipment

User terminal for packet data transmission

Li-ion rechargeable battery provides 1 hour of full power transmit and receive time and 36 hours of standby time

Pokhodnoe Charger: 110/220 VAC, 50/60 Hz

Accessories

Additional power supply with AC/DC conversion, complete with cable

User guide

Additional options

Spare battery

Remote main antenna and antenna GPS receiver

The terminal can be used in an external environment for a maximum duration of up to 36 hours under the following conditions:

Operating ambient temperature: from -10 C to +55 C

Permissible relative humidity: 95% at 40 C

Mechanical vibration: 200-2000 Hz, 0.3 m2/s3

Shock load: drop from a height of 0.5 meters onto a concrete surface without packaging is allowed

Solar radiation: 1120 W/m; MIL-SPEC 810E 505.3

Dust and waterproof: in accordance with IP-54 standard

Figure 94

1. Built-in antenna

3. Installation connector SIM cards

4. Battery

5. Connector external source nutrition

7. Indicators

8. Ethernet adapter

Let's look at the most popular models of Inmarsat satellite phones:

Portable satellite phone Thrane&Thrane TT-3060A is a lightweight, compact and convenient satellite phone for receiving and transmitting telephone, fax messages, data and Email anywhere in the world.

Figure 95

Portable satellite phone NERA WorldPhone Office - no matter where you are, you will always be in touch with Nera WorldPhone Office. An ideal assistant for a businessman, weighing just over 2 kilograms and the size of a laptop computer, Nera WorldPhone Office combines a telephone set, an antenna (built into the lid), an interface to a fax and a computer in one case.

Figure 96

Fixed satellite phone TT-3066A Capsat "Big Dish" is a real alternative to laying a telephone communication line and installing a fixed device. Now it has become possible from almost any hard-to-reach area of ​​the Earth to instantly contact any subscriber in the world by phone, as well as send a fax, data or email mail.

Figure 97

Fixed satellite phone Nera WorldPhone Provident - a satellite phone with an enlarged antenna, used primarily in areas with a low density of communication services. "Provident" allows, in the shortest possible time, with a small initial investment, compared to other communication systems, to equip territories with high-quality communications that were previously not accessible to terrestrial communication networks.

Figure 97

The TT-3062D car satellite phone will turn your car into a modern communication center, providing real independence and high-quality reliable communication anywhere in the world. With its compact design and robust body, the TT-3062A can be easily installed in most modern vehicles. It can be controlled from the handset, like a regular GSM phone, or (via a data interface) from a computer. It is possible to connect a regular telephone (instead of a handset). The antenna and handset can be removed from the main unit by 70 meters.

Figure 98

Odyssey Satellite Communications System

Medium Earth orbit satellite system personal communication Odyssey was developed by TRW and Teleglobe Inc., which included 12 relay satellites in the space constellation, located in three circular orbits. The orbital altitude is 10.4 thousand km. To provide a global view of the Earth, satellites are located in three planes with an inclination of i = 55°. There are 4 satellites in each orbit, which allows for simultaneous visibility from the most important regions of the earth’s surface (from the point of view of the service market) of two spacecraft at once. The ability to simultaneously observe two satellites allows ground terminals to work with a high elevation angle (more than 45°) practically anywhere on Earth. This circumstance significantly increases the reliability of radio communications, since high-rise buildings and other obstacles will have virtually no effect on the propagation of signals.

The system uses wideband signals and a code division multi-station access method. The information transfer protocol is fully compatible with the protocols of cellular radiotelephone communication systems.

Gateway stations

To ensure communication between mobile subscribers and subscribers of the landline public telephone network, as in other MEO systems, gateway stations are used. Each such station has four tracking antennas with a diameter of 3.3 m, which can be located 30 km from the main equipment. Three antennas are used for operational communication with satellites, and the fourth is used to transmit service information to satellites. Since the Odyssey system does not use inter-satellite communications, the area served by each satellite is strictly tied to certain regions of the earth's surface. This is ensured by the fact that the satellite antennas form 10 beams with a radiation pattern width of 5°, each of which is directed to the corresponding observation area.

Since the user terminal is always located in one of the surveillance zones, communication with various subscribers is carried out through a satellite and a gateway station, which provides access to the public telephone network.

It is assumed that the main users of the system will be government services and authorities that need operational mobile communications, as well as part of the population living in remote areas with a poorly developed landline telephone network. The estimated cost of the project is approximately 1.2 billion USD, and the expected number of system subscribers is about 2 million. The cost of a minute of telephone communication is 0.65 USD.

The system developer (TRW company) received a license from the US Federal Communications Commission in 1992 to conduct experimental work with the terrestrial segment of the system.

ELLIPSO satellite communication system

The Eilipso system was developed by Ellipsat Corp. (USA) together with companies from Israel, Canada, Mexico and Australia. Ellipso System Designed to develop telecommunications services for the benefit of underserved users existing means mobile and landline telephone communications. For this purpose, since 1995, a space segment has been created, consisting of relay satellites located in medium-altitude elliptical orbits (8 thousand km altitude), and ground-based means of direct access of subscribers to the system.

Features of building an orbital constellation

The Eilipso system is unique in the sense of dividing the almost global service area into two sub-zones: northern and southern. When conditionally dividing the earth's surface, the developers took into account that in the northern hemisphere above (40° N, W) the population density is much higher than in the southern. In the northern hemisphere above 40° N. t. almost all of Europe, half of the USA, part of Japan and the entire SNA and Canada are located. In the southern hemisphere, the population is concentrated mainly in the territory from 0 to 40 ° S. w.

These features were taken into account when designing the system, which led to the creation of two orbital constellations of spacecraft. The parameters of the spacecraft orbits of both orbital groups are given in Table.

The space segment of the Ellipso system to provide a global view of the Earth's surface consists of two orbital constellations of spacecraft.

Orbital constellation of 6 Concordia spacecraft

14 satellites in 3 orbits

First orbital constellation The spacecraft (Or Borealis consists of 8 satellites, which are located in two inclined i = 116.6º elliptical orbits, and is designed to serve the northern hemisphere of the Earth. The apogee and perigee of the orbits have altitudes of 7840 and 520 km, respectively, while the satellite orbital time is about 3 h.

The second orbital constellation (Or Concordia) consists of 6 satellites located in a circular equatorial orbit at an altitude of about 8 thousand km and serves mainly the southern hemisphere of the Earth, completely covering the tropics of the northern and southern subzones.

In the future, it is planned to increase the number of satellites to serve the northern hemisphere to 12. They will be in two elliptical orbits. The launch of 3 additional satellites will make it possible to implement the entire volume of communication services in the northern and, partially, in the southern hemispheres. By placing 6 satellites in an equatorial orbit, continuous communication is ensured in the tropical zone of both hemispheres. Increasing the number of satellites to 9 will allow for double coverage of 1 region between 40º south. w. and 40° N. w.

The system's satellites are relatively lightweight (688-730 kg). The satellite antenna forms 8 beams, which operate in the L and S bands to communicate with subscribers. The radiation power of the onboard transmitter is 20-25 W. It is planned to use one launch vehicle to launch satellites (up to 5 pieces) into working orbits.

Subscriber stations

The Eilipso system is designed not only for the provision of mobile personal communication services, but also for the transmission of telefaxes, paging and e-mail. If necessary, the system can provide services for determining the location of objects.

For this purpose, pseudo-random sequences are used, which form the NPS in the L- and S-bands. Except known benefits using ShPS, the Ellipso system has the ability to change the polarization of signals in different beams of the on-board antenna, which significantly increases the number of communication channels. The ShPS parameters are chosen close to those recommended for the standards of terrestrial cellular code division networks. This approach will require minimal costs when modifying subscriber terminals for their use in cellular networks radiotelephone communications.

Communication with relay satellites will be carried out both through gateway stations and through user terminals, which can operate in two modes. In the first mode, communication with relay satellites is carried out, and in the second mode, work is ensured in ground-based cellular systems communications.

The process of putting relay satellites into operation includes several stages. At the first stage, 8 satellites will be launched into elliptical orbits to provide communications coverage to the northern hemisphere of the Earth. At the second stage, 6 satellites should be launched into equatorial orbit.

Further satellite launches will be carried out based on market needs, in each country where it is planned to use Ellipso system, it is necessary to install at least one gateway station and a regional network center for interaction with cellular and general telephone networks.