Globalstar is similar to the Iridium network, a satellite communications network. This satellite constellation is based on 48 satellites that pull in about 1,400 km above the earth.
The company Global Star was founded by a merger of the world's leading phone companies and equipment manufacturers such as Qualcomm, Alenia, China Telecom ( HK), DACOM, DaimlerChrysler Aerospace, Elsacom ( a Finmeccanica company ), Hyundai, TE.SA.M ( a France Telecom / Alcatel company ), Space Systems / Loral and Vodafone AirTouch. The company is managed by Loral Space & Communications.
System architecture and differences to Iridium
The orbital inclination of the Globalstar satellite is 52 degrees (Iridium 86.4 degrees). This Globalstar (as well as Inmarsat ) does not cover the polar ice caps. These are supplied only via the Iridium network.
Since the Globalstar satellites have no contact with each other, only calls can be diverted if at the same time is a ground station in the coverage zone of the respective satellites. So must be a Gateway to Global Star within a radius of 3000-3500 km, so that the network can be used. In contrast, Iridium calls are routed via Satellite Inter links to the gateways in Arizona (USA ) and Italy, intra-network calls are routed directly via the satellite.
With Globalstar network calls itself always about on the ground located gateway and possibly the conventional telephone network infrastructure ( PSTN) are routed.
On the high seas as well as in large parts of Africa and South Asia, the Globalstar network has partly no reception, although the satellites cover these areas theoretically. Through so-called extended coverage (via reflection of the signal at the sea surface ) but partly also a reception on the high seas (complete Caribbean and large parts of the North Atlantic ) is possible. However, the quality here is inferior to an even wider range of variation.
Currently (as of January 2007) are the Americas (North, Central and South America), Europe ( North, Central and Southern Europe ), Middle East, North Africa, Australia / New Zealand and much of Asia covered. End of 2009, another gateway in Nigeria went into operation, the large parts of West Africa supplied. However, only simplex data connections are via this gateway previously possible. After long negotiations, the conditions for the operation of a gateway in South Africa were currently created. The start of the gateway, however, is not planned before 2009, as the investment is economically sound in technology of the new generation.
Before using the system, the current supply card of the respective service provider should be consulted.
The operation of the Globalstar system is different gateway operators, each serving a separate region:
- Elsacom for Nord/Mittel- and Eastern Europe (since March 30, 2011 TT). The coverage area of Elsacom was divided between Globalstar Europe and Globalstar Avrasya.
- Globalstar Europe for West / Central Europe
- Pivotel for Australia
- Globalstar Korea / Globalstar Asia Pacific for Korea and parts of Asia ( Pacific)
- Globaltel for Russia
- Globalstar Argentina ( TE.SA.M. Argentina) for parts of South America
- Globalstar do Brasil for Brazil
- Global Star Peru ( Peru TE.SA.M. ) for Peru, Ecuador, Bolivia
- Globalstar Americas for Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panamá
- Globalstar Mexico for Mexico
- Globalstar Canada for Canada
- Globalstar Avrasya (Eastern Europe excluding CIS, Eastern Mediterranean, parts of North Africa )
- China Spacecom ( no longer in operation, field of Globalstar Korea accepted)
The Globalstar network itself is strictly speaking exclusively of the 48 satellites. This so-called Globalstar Air Interface ( GAI ) supports phones to ANSI -41 standard and equipment according to the SIM- based GSM standard. So most gateways contain the necessary infrastructure for ANSI -41 and an MSC for the switching of calls to GSM standard. At present, however, and the Caribbean is only supported the ANSI-41 standard in small areas in the region of Southeast Asia, in which an application of the devices in the service provider is required. A SIM- based roaming is not possible here.
Accordingly, there Telit and Ericsson GlobalStar/GSM900 devices according to the GSM standard, which are based on sim cards and also allow SMS sending and receiving according to the GSM standard. Qualcomm provides an ANSI -41 compliant CDMA / AMPS / Globalstar Tri Mode device and a working also to ANSI -41 standard pure Globalstar handset. As a major difference besides the missing simcard is to see the limitation of SMS. So only messages with a maximum length of 35 characters can be received, which must be sold through a Globalstar web interface. Due to the different standards is a direct Receiving SMS from GSM networks is not possible, as there is no possibility to send SMS messages. One advantage of these devices, however, is the support of Packet Switched Data Service ( similar to GPRS), which is not supported by the Telit devices, but in any case not network is available throughout Globalstar. With the Ericsson device data transfers is only available in GSM mode. Due to the RoHS only the Qualcomm GSP -1700 will be available in Europe in the long term, which has at the request of Globalstar Inc. no terrestrial mobile component more. In addition, offer both Ericsson and Qualcomm for built according to the respective standard.
It should be noted that not all Globalstar providers have roaming agreements concluded among themselves, so that does not automatically cover is guaranteed throughout the Globalstar network. Furthermore fall during operation of the equipment in the coverage areas of an external gateways additional roaming charges, so that the selection of the service provider should be made based on the destination country. While supplies among others such as Germany, France and the UK by Globalstar Europe, while Italy, Switzerland and Austria are covered by Elsacom. A distinct advantage over other satellite system operators is that the participants a conventional mobile number is allocated to the country code of the gateway operator, eg 33638, 33640 and 33641 for Globalstar Europe ( France) or 39310 for Elsacom (Italy). As for incoming calls in the service area of the home gateways are no additional costs, a Globalstar satellite phone within the home gateway is thus much cheaper to reach than other satellite networks.
The international Globalstar country code ( 8818 / 8819 ) has already been allocated, but is only used by Globalstar do Brasil. The assigned by the ITU network identifier was 901-04, but this was now returned.
Some providers also offer roaming agreements with local GSM or CDMA operators, so that on locally available networks an indoor supply can be achieved.
Globalstar provides a higher data transfer rate ( baud = 9600 GSM CSD) as the Iridium network (2400 baud). Furthermore, a low-cost simplex data service for tracking solutions is offered, in which the transmitter according to a predefined interval packets are transmitted with position data. These messages are not acknowledged. After receiving the first message arriving later identical packets are dropped and not charged.
Its own separate Globalstar contract is for the use of the Globalstar network is not absolutely necessary, as there are roaming agreements with GSM operators. Iridium, however, has not entered into roaming agreements with the restructuring of the Group, so that (in spite of the limited supply) may well have advantages for the casual user Globalstar. However, since the Globalstar network is operated over several autonomous gateway, separate roaming agreement with the desired gateway are required. A roaming agreement with a single gateway is thus not automatically mean that roaming throughout the network works.
Total operating costs of the Globalstar network compared are significantly lower than that of the iridium network. But can occur much higher call rates than with use of other satellite networks due to the complex tariff structure and the division into zones especially when using external gateways for the end user.
The Globalstar satellites orbiting the earth at about 1414 km altitude. This height is usually shunned for satellite orbits due to the Van Allen Belt. Cause of the degeneration of the S-Band transmitter is the " South Atlantic abnormality " on the basis of which are exposed at almost any current greater cosmic radiation, the satellites, which negatively impact the electronic components of the satellite. The Globalstar satellites especially the amplifiers of the S-band satellite antennas suffer. About the S-band satellite antenna of the Globalstar satellite phone calls ( Two-Way Voice) and the two-way data transmissions (duplex data service ) are expected.
In the meantime (August 2013) Globalstar has completed the launch of the second generation of satellites, all new satellites are enabled, so that the Globalstar network now again fully functional. During the year 2013/2014 more gateways in Singapore, Nigeria and Panama should expand the coverage area of Globalstar addition.
Within the next few years is planned to replace eight satellites, which were launched in 2007, as these also belong to the old generation.
From 2007 to 2011 was expected to partly massive problems during phone calls and two-way data transmission over the Globalstar satellites. Simplex data connections (eg for tracking solutions ) are not affected. Telephone calls ( Two-Way Voice) and two-way data transmissions (duplex data service ) were, for example, in October 2006, and even after, before and during the preparation of satellite constellation to the new satellites is not always possible .. Statistics for S-band problem provides the Frost & Sullivan study from 2008. Comparing the measurement results of 2008 with the measurement results from 2002, the drop in performance of the S- band amplifier is clearly visible ( because of the harmful radiation).
To defuse the S-band problem, four new satellites of the old generation were placed in orbit ( NORAD 31571, 31573, 31574, 31576 ) on 29 May 2007 from the Soyuz operator Starsem. On 20 October 2007, four more satellites ( NORAD 32263-32266 ) followed also from the Baikonur Cosmodrome. The eight new, fully operational satellite to compensate for the failures of the old satellite. In the meantime (July 2008 ), all eight new satellite has been activated and the quality of care has improved significantly, even if it is very dependent on the own latitude and longitude. However, Globalstar provides on its website a tool to calculate the supply times for free.
According to the press release is to replace the 32 remaining first-generation satellites from the summer of 2009, the second -generation Globalstar satellites. The first generation of satellites was the beginning of a total of 52 satellites in orbit. Of these, 48 satellites in service and four reserve. Due to the S-band problem it Globalstar was no longer possible with the in -spare- orbit satellites (ie the spare satellites in orbit ) and the on-board agents of the individual concerned Satellite ensure network operation. Therefore Globalstar decided to make the eight spare satellites on the ground and ready to use. These eight other first-generation satellites were no longer exposed to 1414 km but 920 km altitude and orbit the earth thus below the problematic Van Allen Belt. The first of the new satellite ( then already the second generation ) will be starting in 2010 also exposed to this amount.
Currently, hence the satellite component works probably again with 48 satellites but without spare satellite in orbit. Since there are currently (June 2010), for example, in Central Europe, only about 50 % of the time a Globalstar satellite for phone calls is available, the question arises how many satellites at all are still in operation, or how weak the amplifier on board the same already.
The Call Times Tool the availability of the network can be calculated for any point on earth.
The Second Generation satellites are do not support satellite Interlink. Therefore Globalstar plans to expand its network gateway as part of the upgrade to the new generation of satellites.
On 14 January 2010 Globalstar started existing gateways in Argentina, Australia, Botswana, France, Korea and the USA convert to the new system. The focus here was the Telemetry Control Unit ( TCU), since the largest differences to the "old " system exist. Since the 24 new satellites in principle pure " amplifier " are used, these are seamlessly compatible with the existing infrastructure and equipment already on the market. In the future, this should be enough 24 satellites for the entire cover of the previously already served regions and little by little replace the getting on in years old satellites. The new generation Globalstar satellites is also intended to have an improved telemetry system that provides greater control over the Globalstar Satellite Operations and Control Center in California.
The validation tests (temperature / vacuum tests) for new satellites have been completed and announced the first time window for a launch of first six satellites of the new generation for a 90 - day period from 5 July 2010. On 19 October, the first six satellites were successfully launched by a Soyuz into space. Two of the satellites will be put into operation within one month. The remaining four early in the year 2011.
As of May 2011, the remaining 18 new satellites are each in three consecutive starts in 3- month intervals, are transported into space. On 13 July and 26 December 2011, two days after the scheduled start, carried a launcher of the Soyuz - 2.1a six Globalstar -2 satellites into orbit.
Up to six satellites should be launched in mid-2012, and will serve to further gap filling and reserve, the replacement of the satellite is complete. By mid-May 2012, the last, not yet active, new satellite should be positioned and activated.