The implementation of the concept of creating personal communication networks provides for the provision of a wide range of services under the motto "anywhere, anytime" using a single personal subscriber number. The work is carried out on the basis of the global integration of existing and emerging networks of fixed, terrestrial mobile and satellite communications, the creation of special terminals that ensure the interface of communication standards and protocols. Within this integration, the satellite phone has a special position as it provides global coverage.
Communication with space
In most people's minds, satellite communications are something exotic from the James Bond movie series. In fact, millions of inhabitants of the planet have a mobile satellite phone, who need to be in touch 24 hours a day, 365 days a year, anywhere in the world. As a rule, subscribers of dozens of firms providing space communications are businessmen, senior officials of large companies, government agencies, geologists, researchers, travelers, less often ordinary people living in remote areas.
Personal Satellite Communication Systems (SPSS)
Since 1985, the International Telecommunication Union has been developing the concept of globalization and at the same time personalization of communications on a global scale. 10 years later, a landmark world conference was held in Buenos Aires, at which the scale and parameters of the global information infrastructure were approved. It consists of a single interconnected system "personal telephone - satellite communications - terrestrial communications".
In solving the problems of globalization and personalization of communications, MSS systems represent the only economically viable solution for reaching hard-to-reach, remote and sparsely populated regions of the planet.
Main objectives of the project
- Globalization of communication - provision of communication services regardless of the location of the user.
- Personalization of communication - bringing services to end users who want services.
- Personal terminal (satellite phone, data transmission devices) - users have means of communication with a personal number.
- Public services for personal users.
- Private service - for certain user groups.
Classification of communication systems
Distinguish between high-speed and low-speed communication systems.
- Low speed: Iridium, Globalstar, ICO, Odyssey, Signal, ECCO, Rostele-sat, Ellipse, Archimedes, Polar Star and others. Range of rendered services: telephony, fax, data transmission. At the momenthigh-speed information transfer is also implemented. For example, a modern Iridium satellite phone provides both stable secure voice and network communications.
- High-speed: Celestri, Spaceway, Skybridge, Teledesic, Secoms and others. They specialize in global interaction services, such as high-speed Internet access, remote user access to databases, high-quality video telephony and conference calls, multimedia services based on various modifications of communication terminals, including basic ones, aimed at a wide range of personal users.
Project Iridium
Back in 1987, long before the ITU World Conference, Motorola conceived an ambitious project of global communications, available around the clock anywhere in the world. The project was named Iridium. Initially, it was supposed to put 77 spacecraft (SC) into low orbits, but after recalculations, the number of satellites was reduced to 66.
To carry out work on the project in 1993, the international consortium Iridium Inc (Washington) was created. The structure as investors included the following companies: Motorola, Lockheed Martin, Nippon, Raytheon, Sprint Corp. and a dozen other representatives. From the Russian side, the investor (82 million dollars, 5% of shares) was the leading rocket and space company of Russia GKNPTs im. Khrunichev. She, under a contract with Motorola, launched the Iridium spacecraft with the help of the PH Proton. The first call via satellite phone was madesummer 1997.
Collapse and rebirth
The main constellation of satellites was launched in 1997-98, and the start of commercial operation is considered September 23, 1998. However, the greed (unreasonably high tariffs) of the managers led to the bankruptcy of the project a year later. Motorola faced the issue of de-orbiting satellites, which required $40 million.
Fortunately, there were investors who believed in the effectiveness of the project. Established in 2000, Iridium Satellite LLC purchased the assets for $25 million and, after securing orders from the US Department of Defense, resumed commercial operation of global satellite systems. In 2009, another reorganization was required - Iridium Communications Inc. became the end user.
Current State
Now Iridium is a quite successful project with a subscriber base exceeding half a million customers. Among them are the most influential figures on the planet, heads of major firms, government services from different countries, employees of transport, construction, mining companies, emergency services and other categories. In principle, anyone can purchase an Iridium satellite phone with a set of services.
Equipment
Iridium Communications manufactures most of its high-speed data and voice equipment in-house. Both "inexpensive" and flagship satellite phones made in a secure case are available to customers. The most popular models are Iridium9505A, 9555 and Extreme (9575). Internet availability is provided by 9522A, 9522B and 9602 modems, and automatic M2M data exchange is provided by Iridium 9601 and 9602 devices.
To save energy, the devices are equipped with monochrome displays. Phones have a high degree of protection against shock, moisture, dust, temperature extremes. The most recent model is the Iridium Extreme satellite phone (9575). This is a fairly portable device in comparison with its predecessors and analogues of competitors. The phone works anywhere in the world and provides the most reliable voice, data and GPS positioning. The Iridium 9575 combines the functions of the Iridium 9555 satellite phone and the Shout Nano satellite GPS tracker. The model has the following features:
- Protected against dirt, vibration, shock, water (IP65, MIL-STD 810F).
- Built-in GPS navigator.
- Programmable SOS button.
- Built-in radio beacon to help search at sea.
Services
The Iridium system provides subscribers with the following services:
- Voice communication. The speech encoder uses a vector-sum excited linear prediction (VSELP) algorithm. The speech rate is 2.4 kbps. Duration of negotiations in 30 sec. (without interruption of communication) will be provided with a probability of 98%.
- Data transfer. Transparent transmission with a variable message length is performed. It is also possible to send short messages that determine the location and status of the subscriber.
- Facsimilemessages. The terminal is able to receive and store messages in memory, the subscriber can view them by scrolling the message on the display screen.
- Personal call.
- Location determination.
Project Thuraya
Unlike the global Iridium network, Thuraya is a regional project operating primarily in Europe. If Motorola and partners have launched 66 spacecraft, the European project is content with three suspended in geostationary orbits. However, a satellite phone connected to the Thuraya system (from Arabic - the Pleiades constellation) will also be able to receive / send calls in Australia, Africa, and Central Asia. A separate brand has been created for Internet communication - ThurayaDSL.
Statistics
A company registered in the UAE is doing a profitable business. It has a subscriber base approaching 300,000 customers, with revenues in 2006 alone exceeding $80 million. For comparison, the company ended 2005 with a positive balance of $26 million.
Equipment
If we compare Iridium and Thuraya equipment, for example, satellite phones, the photos clearly show their external and functional differences. Many Thuraya devices are equipped with compact (retractable) antennas, while the signal level is more than stable in the area covered by the satellites (as noted in user reviews).
Externally, the satellite phone "Thuraiya" resembles "tubes" of cellular communicationmid-2000s: small case dimensions compared to competitors, color screen, more or less modern design. At the same time, the devices have the necessary degree of protection. But, most importantly, the devices are equipped with a GSM module, that is, in the coverage area of cellular communications, if there are service providers with whom the Arab company has concluded an agreement, the phone works like a regular cell phone. If there is no GSM connection, it will automatically connect to satellites.
User functionality of the devices is the same as that of conventional mobile phones: convenient user menu, Java games and applications, data transfer, USB interface. Of the "adult" functions - an advanced GPS system.
Thuraya XT satellite phone
This is the flagship of the Thuraya company, which has become the first among analogues with increased protection against dust, harmful substances and moisture, IP54 / IK03 class. The shock-resistant case made of polycarbonate materials, as noted in the reviews, can withstand severe drops and vibration. Additional resistance to aggressive environments is provided by rubber gaskets and aluminum coating.
Specifications:
- The 262000K color display measures 2 inches and has a resolution of 176x220 pixels.
- Fax and data transmission is possible both via dial-up (low speed, about 9.6 kbps) and via GmPRS (upload - 15 kbps, receive - up to 60 kbps).
- Determination of GPS coordinates with saving the last ten readings.
- USB, standard headphone jack (3.5 mm), ambient light sensor.
- SAT frequencies: sky/ground - 1525/1559 MHz, earth/sky - 1626.5/1660.5 MHz.
- Dimensions (width/height/thickness): 53/128/26.5 mm. Weight - 193 g.
Services
- Voice communication and SMS via satellite phones.
- Facsimile and internet via phones.
- ThurayaIP allows you to transfer data at a speed of 444 kbit/s to a special terminal.
- Determination of GPS coordinates.
- Emergency call for help.
- Voice mail, WAP, missed calls, call waiting, call back, news and other services.
Conclusion
Companies "Iridium" and "Thuraiya" in the provision of seemingly identical satellite communications services have a completely different concept and scale of activity. If an impressive constellation of satellites is involved for the North American project, then three, operating in geostationary orbits, are enough for the Arab partners. An absolute advantage of Iridium is uninterrupted communication throughout the Earth, and Thuraya's trump card is more modern and convenient phones that can work in GSM networks.
