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MXPA99003798A - Dual mode symmetric/asymmetric communication control system - Google Patents

Dual mode symmetric/asymmetric communication control system

Info

Publication number
MXPA99003798A
MXPA99003798A MXPA/A/1999/003798A MX9903798A MXPA99003798A MX PA99003798 A MXPA99003798 A MX PA99003798A MX 9903798 A MX9903798 A MX 9903798A MX PA99003798 A MXPA99003798 A MX PA99003798A
Authority
MX
Mexico
Prior art keywords
user terminal
communication
transceiver
satellite
mode
Prior art date
Application number
MXPA/A/1999/003798A
Other languages
Spanish (es)
Inventor
A Hassan Amer
L Reinhold Stanley
Rutger Rydbeck Nils
Original Assignee
Ericsson Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ericsson Inc filed Critical Ericsson Inc
Publication of MXPA99003798A publication Critical patent/MXPA99003798A/en

Links

Abstract

A satellite-cellular communication system includes a satellite based transceiver for transceiving two-way communications originated at a user terminal. As a part of call set up, controller determines whether the user terminal should transmit in the uplink in either a wide band mode of operation or in a narrow band mode of operation. The controller then specifies to the user terminal the mode of operation through the transceiver. Whether the user terminal transmits in the uplink in a wide band or in a narrow band mode depends upon factors including the type of device, channel usage and efficiency in the channels to and from the satellite transceiver and the signal quality of the signals received at the transceiver.

Description

SISTI-lLß- BE SYMMETRICAL / ASYMMETRIC CONTROL FOR COMMUNICATION IN DUAL MODE BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention relates to a communication system that can operate to carry communication signals between satellite transceivers and terrestrial-based transceivers, and in particular, to a system that includes operable transceivers for communicate with a selected one of two or more carrier protocols used in different types of cellular communications systems. Description of Related Art Cellular land communications systems are now commonly available for subscriber use in most of the major urban areas of the world. However, despite the success of these systems and the growing demand for extended coverage, there are still areas of the world where cellular land communication systems do not present a commercially possible communication option. For example, rural areas with low population density do not offer a potential and sufficient subscriber base to justify the cost of installing the infrastructure of a mobile cellular system. terrestrial communications. It should be noted that these rural areas sometimes lack conventional wireline (fixed) telephony service for the same economic reasons. There are also aspects of capacity with respect to existing cellular terrestrial communications systems. The success and drastic acceptance of this form of communications has given rise to an increase in the growth of the subscription. With more and more users, some of the cellular communications systems are overloaded during peak usage times. Although the demand that justifies the expansion is present, some service providers have been slow to respond to the growing demand and have not extended or made plans to extend the existing infrastructure to support the new demand. In some cases, government limitations have impeded the effective response of service providers to the growing demands. In other cases, the development of terrestrial cellular technology to handle the growing demand for cellular services has not produced the promised results as quickly as expected. The aforementioned aspects have contributed to the development of cellular satellite communications systems. These systems depend on the satellites of communications placed in orbit on the surface of the earth to retransmit telephone communications between cellular devices capable of originating or terminating two-way communications (also known as "user terminals") with satellite-based transceivers. A benefit, from the perspective of service and cost, provided by a cellular satellite communications system is that a single satellite is capable of serving the necessary communications of many users distributed over a substantial service area that includes rural areas and urban. In fact, a satellite may be able to provide communications service through all of a country. The satellites are also capable of providing communications service in remote areas of the world where the infrastructure installation of the cellular and wireline communications system, conventional, is difficult if not impossible. Although satellite-based communication systems can solve problems related to providing communications services in remote areas, it is generally accepted that it is preferable to use a terrestrial network if one is available. The reasons for this refer mainly to the quality of the service. The cellular systems of terrestrial communications and the system of cellular communications by satellite, however, operate according to different protocols and communication standards. -Further, there are many types of cellular terrestrial communications systems, again each operating in accordance with different standards and communication protocols- In this way, for example, a subscriber who wishes to have access to and use the cellular satellite communications system of the Asia type Cellular Satellite (ACe?) Or SATCOM must own and use a mobile station configured for operation in accordance with the ACeS communications standard. If the same subscriber wishes to have access to and use the cellular system of communication type communications Global System for Mobile (GSM), his mobile station must be configured for the operation in accordance with the GSM communications standard. In the same way, the mobile station must be suitably configured for operation in any other desired cellular terrestrial or satellite communications system (such as a cellular satellite communication system type I-CO, or the Advanced Mobile Phone type). System (AMPS or D-AMPS) or cellular communications systems type Personal Communications System (PCS)). Recent developments in the design of the mobile station have made multiple-mode mobile stations available to subscribers. These multiple mode devices are capable of being configured for operation in any of two or more types of cellular communication systems available that has been selected. For example, the mobile station can be configured for operation in a mode according to the GSM communications standard, and in another mode according to the PC communications standard ?. With the advent of cellular satellite communications systems, more and more mobile stations will be able to operate in one of the cellular terrestrial communications systems, such as GSM, and one of the cellular satellite communication systems, such as the ACeS. Access to this mobile station, together with the possibility of operating cellular terrestrial and satellite communications systems, advantageously provides the subscriber with access to communications services practically all over the world. Currently, a mobile station or other operable system to originate or terminate two-way communications with satellite-based transceivers (collectively "user terminal" or "UT") receives downlink, broadband and transmits narrowband, uplink signals. The narrow band is defined herein as 50 kilohertz or less and the broadband is defined as 200 kilohertz or greater. Although some of the dual-purpose user terminals before described are capable of broadband communications with terrestrial networks, by way of example GSM, these are designed to communicate with satellite transceivers in a narrow band when operating as a user terminal. One reason why mobile stations operating as a user terminal can not transmit to a satellite-based broadband transceiver is that legal regulations prevent the average transmission power level for mobile stations above a specified amount. This specified amount is a value that does not allow broadband transmission that are strong enough to reach a satellite receiver. A mobile station that operates as a user terminal must, therefore, transmit on an uplink to a satellite transceiver. satellite in a narrow band mode to increase the average power of the transmitted signals. The narrow band transmission mode is necessary to overcome the significant amount of attenuation of life to the atmosphere and distance to the transceiver. In addition, even without legal limitations, the limited power of a mobile station prevents broadband broadcasts with sufficient power from reaching a satellite with sufficient clarity. Currently, a large number of existing user terminals transmit on an uplink towards the satellite transceiver at a very narrow bandwidth, namely 5 kilohertz. Examples of user terminals currently transmitting in this narrow bandwidth for the uplink portion of two-way communications include mobile stations, communication devices installed in automobiles and large communication devices mounted on roofs used by large shopping centers, tall buildings, hospitals, etc. Although the user terminals originate or terminate a communication signal with a satellite transceiver transmit in a narrow band mode in the uplink, the ground stations (LES) are designed to transmit in an uplink, in an operation mode broadband This is important because the LES are operable as an interface between a satellite transceiver and a terrestrial communication system and have high performance requirements. Despite the fact that the current user terminals all transmit on a narrowband uplink, it is advantageous for a user terminal to communicate with a satellite transceiver in the uplink in a broadband mode in many cases. Because satellite transceivers communicate in a downlink in a broadband mode, the balance and symmetry of the Communication can be carried out better if the communication links on the uplink are also in a broadband communication mode. This balance simplifies timing problems of communication in certain situations and improves the functioning of general communication. The current user terminals are not designed, however, to communicate with satellite transceivers in a broadband operation mode. Even if a user terminal is designed to transmit in a broadband mode in an uplink to a satellite transceiver, it is preferred in some cases that the user terminal transmits in a narrowband mode for the uplink. A situation in which it could be advantageous for a communication device to transmit in a narrowband mode in the uplink, for example, is to improve the reception quality of the signal by the satellite transceiver. The quality of reception of the signal can be improved by reducing the speed of the data to increase the amount of average power for a defined amount of signal. For some communication systems, by way of example, a satellite communication system, it is known that the attenuation of the signal path is sufficiently large that requires that a mobile station communicate in a narrow band communication mode for the signal to reach the satellite transceiver. Star communication networks usually include a controller for channel management. Because this controller is usually designed to allocate channels in an efficient manner as part of its channel management, the controller is adapted to determine the communication links that are available and allocates the channels as necessary. However, given the continuing need for limited bearer resources, there may be times when it is desired that a user terminal capable of broadband communication be established for communication in a narrowband carrier. For example, if the only available carrier (or channel) is a narrowband carrier, a ground base station that is adapted for broadband communication would have denied access until a time when it attempts to establish a communication link and a link is available. Broadband channel. Therefore, there is a need for a user terminal that is capable of selective communication with a satellite transceiver in a narrowband mode or in a broadband communication mode. There is also a need for communication control systems, in general, to selectively control the protoco-lo of communication and the bandwidth used by the ground station for its uplink to a base station or a satellite transceiver.
COMPENDIUM OF THE INVENTION To solve the needs described above, a system is provided for communication with a satellite over an uplink in broadband or narrowband mode. In addition, a controller is provided for transmitting control signals and for controlling the type of communication transmissions produced by a user terminal on an uplink (return link). The controller sends control instructions to the user's terminal to order which carrier channel to use and whether to communicate in the "broadband or narrow band operation mode." The user's terminal receives the instructions from the control device and responds to them- More specifically, the user terminal, in accordance with the control instructions, will select a channel for communication and use the broadband or narrowband communication mode.
The narrow band mode is usually characterized by a spacing of the 200 kilohertz carrier, while the narrow band is usually characterized by a spacing of the 50 kilohertz carrier.
The controller can also operate to communicate with a telemetry device that monitors communications within the satellite network to determine the transmission and efficiency of the different communication links established between the ground stations, the user terminals and a satellite. specified. Based on the information provided by the telemetry monitoring device, the controller selects channels and modes of operation to increase transport efficiencies, or in some cases, simply to allow a device to communicate over a narrow band in the case of that a broadband channel is not available. Because the system includes the ability to instruct a transmitter with broadband capability to transmit in narrow band, the efficiency of the total communication is increased and the operation of the system is improved. In addition, having a selectable transmission mode as defined herein allows the system to transmit in a narrow band to overcome other system restrictions. For example, if two or more ground stations are communicating via a satellite, the time constraints may require a larger data burst for system-synchronization purposes, in order to improve the overall operation of the system.
A user terminal is also provided to receive specified control instructions on a control channel from a controller- The user terminal selects its mode and communication channels in response to the specified control instructions. A ground station (LES) is provided to carry two-way communications originated by a telephony device. By way of example, the LES can transport communication signals originated by a telephone coupled to the public switched telephone network or by a mobile station. More specifically, the LES is adapted to receive broadband communication signals with a bandwidth of 200 kilohertz and to transmit those signals to a satellite transceiver also at 200 kilohertz.
BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the method and apparatus of the present invention can be obtained by referring to the following detailed description when taken in conjunction with the accompanying drawings, wherein: Figure 1 is a block diagram of a first system of communications that - includes terrestrial and stellar cellular communications networks; Y Figure 2 is a block diagram of a second communication system that includes terrestrial and stellar communications networks.
DETAILED DESCRIPTION OF THE DRAWINGS With reference to Figure 1, a satellite-cellular communication system, generally shown at 10, includes the circuits, and the associated methodology, of one embodiment of the present invention. It should be noted at the outset that, although the communication system 10 is illustrated as a satellite cellular communication system, the present invention can likewise be incorporated into a terrestrial cellular communication system or other telephone radio. For example, as one skilled in the art will appreciate, by the proper substitution of land-based base stations for certain satellite-based transceivers of a satellite cellular communication system, a terrestrial cellular communication system may instead be formed. The communication system 10 includes a land station 12 which is coupled, in this case represented by the lines 14, to a public service telephony network ("PSTN"). The ground station 12 includes transceiver circuits for emitting-receiving communication signals, among others, with a satellite-based transceiver 16 on a communication link 13. The satellite-based transceiver 16 is operable to transmit communication signals not only to the terrestrial station 5 but also to other terrestrial-based devices, such as the transceiver circuits of a network control center 18. The transceiver 16 is operable mainly to retransmit signals generated at the ground station 12 to the control center of the network 10 18 over a communication link 17, and vice versa . The transceiver may preferably receive signals on any frequency channel and retransmit the signal on another frequency channel. The transceiver circuits of the control center of the network 18, in turn, can emit-receive communication signals with other satellite-based transceivers, such as transceiver 22 on communication link 23. Satellite-based transceiver 22, similar to transceiver 16, can emit-receive signals Communication with terrestrial-based transceivers including, for example, a user terminal 24 on a communication link 25. In the same manner as transceiver 16, transceiver 22 operates primarily to retransmit signals transmitted thereto. In this way, the user terminal 24 operates to transmit signals of communication over a communication link 27. The transceiver circuits of the devices illustrated each include a plurality of send-receive elements to allow concurrent communication between large numbers of communication stations. The transceiver circuits of the control center of the network 18, in turn, can transmit-receive communication signals with other satellite-based transceivers, such as transceiver 22 on the communication link 23. The satellite-based transceiver 22, similar to transceiver 16, may transmit-receive communication signals with terrestrial-based transceivers including, for example, a user terminal 24 on a communication link 25. In the same manner as transceiver 16, transceiver 22 is operable mainly to retransmit signals transmitted to it. In this way, the user terminal 24 is operable to transmit communication signals on a communication link 27. The transceiver circuits of the device illustrated each include a plurality of transmit-receive elements to allow concurrent communication between a large number of communication stations. Communication according to the satellite-cellular communication system, such as system 10 that is shown in Figure 1, allows a user of a user terminal, such as user terminal 24, to communicate by telephone when positioned at any location through large areas of the world. Provided that the user of the user terminal 24 is positioned to transmit the transmission and reception of communication signals with a satellite-based transceiver, such as one of the transceivers 16 and 22, the user can communicate by telephone with a user of another user terminal or with a conventional wired network telephone device. Due to the almost universally permitted range of a satellite-cellular communication system, the user of the user terminal 24 can communicate with the transceiver 16 regardless of whether the user terminal 24 can communicate with a local cellular system. Therefore, the user can have telephone communication in an area that otherwise does not have a telephone, cellular or wire network, installed. For example, when the land station 12 (ie, a telephone device coupled to it) attempts to transmit a call initiated with the P? TN to the user terminal 24, an indication of the start is provided to the control center of network 18 by means of transceiver 16. The control center of the network generates signals of control, which are provided to the terminal 24 by means of the transceiver 22 and the LES 12. Once a call preparation is completed satisfactorily, the voice channels between the land station and the user terminal are defined to allow Two-way communication between the ground station and the user terminal, by means of the transceiver 22. As already mentioned, the supervision and control signals must first be sent to the terminal when a call is being placed to or from a user terminal . In the case of an incoming call to a user terminal, these signals are transmitted to inform the user terminal of the incoming call and to cause the user terminal to be tuned to the communication signals transmitted-received according to this call. Included among the supervision and control signals transmitted to the user terminal is a paging or search signal to alert the user terminal of the incoming call. When the user terminal is paged, the user terminal may not be positioned to receive the paging signal. The paging signal must be repeated in such cases so that the user terminal receives the paging signal. If the link margin is increased to send the message, the paging signal includes, in one mode, a signal that specifies that the link margin needs to be increased in the return signals, for example, the recognition signal. Accordingly, the controller 18 aware of the difficulties in transmission uses this information in selecting modes of broadband or narrow communication for the uplink of the user terminal. Following the reference to the system of Figure 1, the ground station (LES) 12 is operable to communicate with the transceiver 16 in a broadband mode (200 kilohertz). The UT 24, however, is operable for communication with the transceiver 22 in a wideband mode or a narrowband (sic) baud (sic) (50 kilohertz). As the LES 12 communicates with the network control center (controller) 18 to establish a communication link, the controller 18 communicates with the telemetric monitoring station 20 to determine the efficiencies and use of the system data channel. The controller 18 determines whether the UT 24 is going to communicate in a wideband or narrowband mode, as well as which carrier or frequency band the UT 24 is going to use in the uplink. To illustrate, the controller 18 may determine that the UT 24 communicates with the transceiver 22 over a specified channel in the communication link 27 in a broadband mode. The way in which the controller actually determines which channel or carrier to be used is known to those skilled in the art. The controller 18 then transmits a control signal over a control channel specified for the UT 24 over the communication links 23 and 25. The control signal specifies which channel and which UT 24 will use a broadband or narrowband operation mode. The controller 18 determines whether a user terminal, in this example UT 24, should use a broadband or narrow band communication mode by analyzing various factors. One factor is the type of user terminal. For certain devices a narrow band is required due to restrictions or limitations on the maximum power level for the device. By way of example, user terminals are usually limited to two watts of maximum power. In broadband communications, the user terminal is limited to 2 watts / 20 users = 0.1 watts / user ----- However, in narrow band communications the user terminal is limited to 2 watts / 5 users = 0.4 watts / user. Because 0.1 watt is not enough power to ordinarily reach a satellite or transceiver while 0.4 watt is sufficient, the controller 18 will direct a user terminal to be transmitted to a satellite transceiver, for example, transceiver 16 or 22 in a narrow band mode even if the user terminal 24 is capable of Broadband communication with other networks such as GSM networks. A second factor that the controller uses is the quality of communication of the signal. If the transceiver 22 sends a control signal to the controller 18 indicating that it is receiving a poor signal quality from the user terminal 24, the controller 18 can instruct the user terminal 24 to use a narrow band. By using a narrow band, a link margin of the transmitted signals can be increased as the average power per signal increases, thereby increasing the quality of the signal. In the same way, if the quality of communication is low due to timing or delays in the synchronization of the signal due, "in part, to the propagation of the delays that remit from great distances of the signal path, the problems of timing can be reduced or eliminated by switching a broadband signal to a narrow band where a protection time between the signals is decreased to a much smaller percentage of the total signal period.A protection time is a period of non-use between transmission bursts used to facilitate system synchronization.
A third reason why a controller could instruct a transmitter capable of broadband, by means of the example LES 12, to transmit in a narrow band is related to the use of the channel. If the controller 12 determines from the communication with the telemetric device 20 that the only or best available channel is a narrow band channel for the uplink, then the controller 18 instructs the UT 24 to communicate in a narrowband mode on the band channel. narrow specific. Reference is now made to Figure 2, where a block diagram of a communications system 100 is shown including a transceiver 16 and mobile switching centers (M? C) 28 and 30. A ground station 12 connected to a mobile switching center (MSC) 28 that connects the LES 12 to the public switched telephone network (PSTN) 32. The communications system 100 includes a plurality of transceivers 16 (only one is shown) placed in orbit on the surface of the earth. The LES communicates with the transceiver 16 via a communication link 34. The transceiver 16 communicates with the user terminal 24 on a radio frequency communication link 36. The transceiver 16 accordingly operates to delay telephone communications. "(and the related control signals) between the LES 12 and the the user 24 on the communication links 34 and 36. The MSC 28 is operable to switch the calls generated by the telephony sources, for example, PSTN 32 or MSC 30 to the LES 12 to transmit signals from communication to the transceiver 16 and to other user terminals, for example, to the user terminal 24. The operation of the satellite cellular communication system 30 in this manner is well known to those skilled in the art, and no further communication will be provided. description. The communication systems 100 include a plurality of base stations (BS) 38 and 40 (only two are shown) to transmit telephone communications (and related control signals) with mobile station 42 over a radio frequency communication link 44. The BS 40 is connected through the mobile switching center (MSC) 30 to other mobile switching centers (not shown) within the cellular communication system 100. The MSC 30- routes within the communication systems 100 calls from other portions of the communication system 100- For example, calls originated by or terminated at the mobile station 42 can be routed to the user terminal 24 through the MSC 30, P? TN 32, MSC 28 LES 12 and the transceiver 16 , respectively. The operation of communication systems 100 in this form is well known to those skilled in the art, and no further details will be provided. Although the communications system 100 is illustrated having only two base stations 38 and 40, it will of course be understood that these systems usually include many more base stations, and that the representation of only two base stations should be taken as an illustration of, instead of of limitation, of the operation of the present invention. It will be understood, furthermore, that while only two mobile switching centers 28 and 30 are shown to simplify illustration, it should be understood that these systems will usually include a large number of mobile switching centers interconnected with each other (perhaps by PSTN 32), each of the mobile switching centers being connected to a plurality of base stations 38 and 40. Finally, the communications systems 100 usually include a large number of mobile stations 42 operating therein at any time . The representation of a mobile station 42 should be considered as illustrative of, rather than a limitation, of the operation of the present invention. Again in relation to the system 100 of Figure 2, the user terminal 24 is operable to communicate -with BS 38 on the communication link 44. If, for example, the MSC 28 and the BS 38 are part of a communication network.
GSM cellular, then the UT 24 communicates in a broadband mode over the communication link 44 when the user terminal is operable as a mobile station in the GSM network. The user terminal 24 is also capable of communication with the transceiver 16 in a broadband mode on the communication link 36 if the user terminal is a type of communication device other than a mobile station. However, it does not matter if the user terminal 24 is a mobile station, it is capable of communication with the transceiver 16 on the communication link 36 in a narrow band mode. As described in relation to the system of Figure 1, the controller 18 operates to send control signals to the user terminal 24 to instruct if it communicates in a narrow or wide band operation mode. If the controller 18 sends control signals to the user terminal 24 to instruct it to communicate in a broadband mode, it depends, in part, on whether the user terminal is a mobile station or another type of communication device. Again in relation to the system 100 of Figure 2, the user terminal 24 is also operable to communicate with LES 12 over the communication link 46 in a broadband operation mode. The LES 12 receives the communication signals from the user terminal 12 and transmits the same signals to the transceiver 16 on the communication link 34 also in a broadband operation mode. The transceiver 16, in turn, transmits by the transceiver the received signals to another user terminal or another terrestrial station. By way of example, the transceiver 16 transmits the communication signals received from LES 12 to the LES 50 if, for example, the termination point of the communication link is the mobile station 42. As can be seen, the LES 50 transmits the signals received to the MSC 30 which transmits them to the BS 40. The BS 40 transmits the signals to the MS 42. By using the corresponding carrier signals in terms of bandwidth in the communication links 46 and 34 , the synchronization problems of the transmissions through the LES 12 are simplified and the efficiency of the communication in general is improved. From the examination of the system 100 of Figure 2, it can be seen that the user terminal 24 is operable to communicate with the BS 38, LES 12 and the transceiver 16 all in broadband mode (200 kilohertz). In addition, the user terminal 24 is also capable of communication with the transceiver 16 in a narrow band operation mode (50 kilohertz or less). Accordingly, the controller 18 is operable to send control signals to the user terminal 24 specifying the communication mode in the link and communication 36. Furthermore, as can be seen, there are multiple communication routes shown for which the user terminal 24 can be used to establish a communication link- The multiple communication routes are shown to illustrate the variety of options. However, in practice it is expected that certain routes are preferred over others. The route used, therefore, is a function of actual availability. To illustrate, if a communication link 44 can be established with the BS 38, the user terminal 24 will operate as a mobile station and will seek to establish a broadband communication link 44 with the BS 38. If the user's terminal is looking for placing a call for the mobile station 42, therefore, a communication path is established through the MSC 28, the PSTN 32, MSC 30 and BS 40 to reach the mobile station 42. However, if the BS 38 is too far to establish the communication link 44, the user terminal is operable to attempt to establish broadband communication link 46 with the LES 12. The LES 12 is then operable to retransmit communication signals received from the user terminal 24 to transmit via the transceiver 16 over the broadband communication link 34. The transceiver 16 then transmits the received communication signals to the LES 50 over the link communication 48. The LES 50 is then operable to transmit the communication signals to the MSC 30, the BS 40 and finally to the MS 42 to create the communication path from the user terminal 24 to the mobile station 42. As an example final, if the user's terminal is too far away from the LES 12 to establish the communication link 46, it seeks to establish the communication link 36 with the transceiver 16. If the communication link 36 is established as a band communication link wide or narrow band depends on factors such as whether the user terminal 24 is a hand held device such as a mobile station and the control signals received from the controller 18 on a control channel transmitted through the communication link 36. The establishment of the call via the control channels on the communication link 36 is well known to those skilled in the art and is not explained á in the present. Accordingly, the user terminal transmits control signals to the transceiver 16 on a control channel within the communication link 36. The transceiver 16 then communicates with the controller 18 over the control channels in the communication path 23 to indicate that the user terminal searches for a communication channel. The controller 18 then analyzes the use of the channel and also examines the type of device that requests a channel. In response to this, the controller 18 transmits control signals back to the user terminal 24 via the transceiver 16 specifying the channel and whether the user terminal will transmit in a wideband or narrowband mode.
Although one or more embodiments of the method and apparatus of the present invention have been illustrated in the accompanying drawings and described in the aforementioned detailed description, it should be understood that the invention is not limited to the described embodiments, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as established and defined by the following claims.

Claims (6)

1. A communication network system, consisting of: a satellite transceiver for receiving and transmitting communication signals; a communication device for terminating a call transmitted by the satellite transceiver; a user terminal to originate a two-way communication and to transmit to the satellite transceiver communication signals, selectively, in a broadband or narrowband mode; and a controller for transmitting control signals to the user terminal, the control signals specifying whether the user terminal will transmit the communication signals in a wide band or in a narrow band.
2. In a cellular communication network system having a satellite-based transceiver, a user terminal for coupling in two-way communications and for transmitting an uplink signal formed of a selectable frequency bandwidth through a satellite-based transceiver to a receiving station, and a controller to allocate a communication channel on which to transmit the uplink signal, an improvement for the control circuits to provide the user terminal with the bandwidth of selected frequency of which the uplink signal is to be formed, the circuits consist of: a receiver of the communication indications to receive the indications of at least the communications indications by the user terminal on the assigned communication channel by the controller. a selector operably responsive to the indications received by the receiver of the communication indications, the selector for selecting the frequency bandwidth of the uplink signal to be transmitted by the user terminal; and a transmitter for transmitting indications of the frequency bandwidth selected by the selector to the user terminal.
3. The cellular communication network system of claim 2, wherein the user terminal is operable to transmit in an uplink in a narrow band mode or a broadband mode. The cellular communication network system of claim 3, wherein the controller is operable to transmit control signals to the user terminal by specifying whether the user terminal transmits in a broadband or narrowband mode. 5. A communication network system consists of: a user terminal for originating a two-way communication, the user terminal for transmitting in an uplink in a broadband mode and in a narrowband mode; a satellite transceiver; a ground station for receiving the uplink transmissions from the user terminal and for transmitting via the transceiver the uplink transmissions to the transceiver, the user terminal and the ground station both transmitting in a broadband mode; and a communication device for terminating the two-way communication originated by the user terminal and transmitted by the ground station and the satellite transceiver. 6. A method for establishing a two-way communication link through a satellite transceiver, originated communication at a user terminal and terminating at a communication device, the method includes the steps of: transmitting from the user terminal to a controller a request for a communication channel; and receive the request for a communication channel and transmit, in response thereto, the control signals from the controller to the user terminal, signal them of control including a mode signal, the mode signal to specify a mode of operation in broadband or narrow band for the uplink from the user terminal to the satellite transceiver.
MXPA/A/1999/003798A 1996-10-25 1999-04-23 Dual mode symmetric/asymmetric communication control system MXPA99003798A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08736954 1996-10-25

Publications (1)

Publication Number Publication Date
MXPA99003798A true MXPA99003798A (en) 1999-10-14

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