A communication system and method
Abstract
A controller of the base station of the mobile network comprising a means for communicating with the cell equipment through a standardized protocol and for communicating with a node of the mobile network through a standardized protocol, in which the The base station controller comprises a central gateway (9) and a physically separated remote gateway (6), in which: The remote gateway communicates with the cell equipment (5, 7) through a standardized protocol for a cell in the remote mobile network, the central gateway (9) communicates through a standardized protocol with a node of the mobile network (10), the gateways (6, 9) make an internal communication of the base station controller between each other using a remote communication link; each of the gateways (6, 9) terminates, without retransmission, some signals received from an external entity in which the remote gateway terminates the radio measurement signaling, and each of the gateways dynamically maps some of the data received from the external interface to lower bandwidth data transmitted over the remote communications link with the other gateway

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Projected expiry passed 2 September 2024, 2.1 years ago.
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40 claims: 22 independent, 18 dependent
- 1ES 2 379 786 T3 REIVINDICACIONES 1. Un controlador de la estación base de la red móvil que comprende un medio para la comunicación con el equipo de célula a través de un protocolo normalizado y para la comunicación con un nodo de la red móvil a través de un protocolo normalizado, en el que el controlador de la estación base comprende una puerta de enlace central (9) y una puerta de enlace remota separada físicamente (6), en la que:la puerta de enlace remota comunica con el equipo de la célula (5, 7) a través de un protocolo normalizado para una célula de la red móvil remota, la puerta de enlace central (9) comunica a través de un protocolo normalizado con un nodo de la red móvil (10), las puertas de enlace (6, 9) realizan una comunicación interna del controlador de la estación base entre cada uno de los otros usando un enlace de comunicaciones remoto;cada una de las puertas de enlace (6, 9) termina, sin retransmisión, algunas señalizaciones recibidas desde una entidad externa en la cual la puerta de enlace remota termina la señalización de medición de radio, y cada uno de las puertas de enlace mapea dinámicamente algunos de los datos recibidos de la interfaz externa a datos de ancho de banda más bajo transmitidos sobre el enlace de comunicaciones remoto con la otra puerta de enlace.
- 2Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 1, en el que el enlace de comunicaciones remoto es un enlace de satélite (7, 8).
- 3Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 2, en la que el enlace de comunicaciones remoto es un enlace de comunicaciones entre la nave y tierra (7, 8).
- 4Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que el enlace de comunicaciones remoto es terrestre basado en radio, de microondas, de cable o de fibra óptica.
- 5Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) termina la señalización del latido desde los nodos de la red remotos.
- 6Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace central (9) termina la señalización de gestión del enlace.
- 7Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace central (9) termina la señalización del latido desde un nodo de la red móvil (10).
- 8Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que cada una de las puertas de enlace (6, 9) elige dinámicamente una portadora adecuada sobre el enlace remoto de acuerdo con la naturaleza de las señales para optimizar el uso del ancho de banda.
- 9Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 8, en el que cada una de las puertas de enlace (6, 9) conmuta dinámicamente entre el uso de los canales de datos y voz del enlace remoto.
- 10Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) extrae un número marcado a partir de múltiples mensajes, y transmite sólo los datos del número marcado desde dichos mensajes múltiples a la puerta de enlace central (9).
- 11Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 10, en el que la puerta de enlace remota (6) añade datos adicionales a los datos del número marcado, y la puerta de enlace central interpreta los datos adicionales para generar señales de la red móvil para el nodo de la red móvil.
- 12Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) usa un campo de señalización de ISDN de usuario a usuario para transferir los datos adicionales.
- 13Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) usa el DTMF para transmitir datos adicionales, y el DTMF se termina en la puerta de enlace central (9).
- 14Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) procesa por lotes las peticiones de actualización de la localización de acuerdo con la naturaleza del enlace remoto. ES 2 379 786 T3
- 15Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) procesa por lotes mensajes de texto o de multimedia de acuerdo con la naturaleza del enlace remoto, (7, 8).
- 16Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la información relacionada con la autenticación intercambiada entre la puerta de enlace central y un nodo de red se procesan por lotes para la transmisión a y desde la puerta de enlace remota que maneja la autenticación de los abonados móviles individuales.
- 17Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que las puertas de enlace (6, 9) usan compresión para al menos alguna comunicación interna sobre el enlace remoto (7, 8).
- 18Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 17, en el que cada una de las puertas de enlace (6, 9) almacena paquetes de voz y combina una pluralidad de paquetes de voz almacenados dentro de un único paquete de transmisión.
- 19Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 18, en el que el paquete de transmisión es un paquete RTP.
- 20Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que las puertas de enlace (6, 9) realizan la transcodificación y la adaptación de tasa en la mayor parte de las puertas de enlace apropiadas de acuerdo con la naturaleza del enlace remoto.
- 21Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace central (9) comprende una función de operaciones y mantenimiento (31) para ambas puertas de enlace.
- 22Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) comprende una función de operaciones y mantenimiento (22) para ella misma y la célula de la red móvil remota.
- 23Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 22, en el que la función de operaciones y mantenimiento (31) descarga hacia abajo actualizaciones a la puerta de enlace remota.
- 24Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones 22 ó 23, en el que la función de operaciones y mantenimiento (22) descarga hacia arriba información de fallos, información de estado y estadísticas desde la puerta de enlace remota.
- 25Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace central (9) mantiene una base de datos (32) de datos pertenecientes a las puertas de enlace remotas con las que comunica.
- 26Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) mantiene una base de datos (25) de abonados registrados para la célula remota.
- 27Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) está enlazada a un sistema de entretenimiento o anuncios públicos.
- 28Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 27, en el que la puerta de enlace remota (6) permite la interrupción de las llamadas por el sistema de entretenimiento o de anuncios públicos.
- 29Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) determina si una llamada o mensaje iniciados localmente son para una persona localizada en su célula, y evita el uso del enlace remoto si este es el caso.
- 30Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace remota (6) es configurable para manejar sólo tráfico de mensajes de texto.
- 31Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 30, en el que la puerta de enlace remota (6) rechaza las llamadas de voz y de datos salientes desde los abonados registrados en la célula de la red móvil remota cuando el sistema está operando en el modo de sólo mensajes de texto.
- 32Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 31, en el que la puerta de enlace central (9) envía una señal al HLR de un abonado registrado para desviar las llamadas entrantes cuando el ES 2 379 786 T3 sistema está funcionando en el modo de sólo mensajes de texto.
- 33Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que la puerta de enlace central (9) detecta cambios de la Región de Océano a partir del mensaje de inicio de sesión de la puerta de enlace remota (6) y a partir de la dirección completa de la nave remota, construye un número marcado correcto completo incluyendo la región de Océano que se usará para terminar las llamadas de voz para cada uno de los abonados.
- 34Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones anteriores, en el que al menos una de las puertas de enlace (6, 9) genera automáticamente una respuesta al nodo de red (10) sin usar el enlace remoto.
- 35Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 34, en el que la puerta de enlace (9) genera automáticamente la respuesta dentro de un periodo de tiempo fijado por el nodo de red al cual está respondiendo.
- 36Un controlador de la estación base de la red móvil de acuerdo con las reivindicaciones 34 ó 35, en el que la puerta de enlace (9) está pre-configurada con normas para generar automáticamente dichas respuestas.
- 37Un controlador de la estación base de la red móvil de acuerdo con cualquiera de las reivindicaciones 34 a 36, en el que dicha puerta de enlace es la puerta de enlace central (9).
- 38Un controlador de la estación base de la red móvil de acuerdo con la reivindicación 37, en el que la puerta de enlace central (9) genera automáticamente una respuesta a una solicitud de marca de clase del MSC (10).
- 39Una célula de red móvil que comprende un controlador de estación base (6, 9) de acuerdo con cualquiera de las reivindicaciones anteriores, y un transceptor de estación base (5).
- 40Un método de comunicaciones entre una célula de la red móvil remota (5, 11, 12) y un nodo de la red móvil central (10), comprendiendo el método un transceptor de la estación base (5) de la célula remota que comunica con la puerta de enlace remota (6) de un controlador de la estación base de cualquiera de las reivindicaciones anteriores, procesando la puerta de enlace remota (6) las señales recibidas desde el transceptor (5) y transmitiendo el controlador de la estación base interna señales a la puerta de enlace central (9) a través del enlace remoto (7, 8).
Independent claims40
205 paragraphs in 13 sections, as filed
ES 2 379 786 T3
DESCRIPTION
A communication system and method
Introduction
Field of the invention
The present invention refers to a communication that involves people in a remote location such as a vehicle or mobile ship, be it air transport, water transport or land transport or in a remote geographical location with few telecommunications resources.
Discussion of the prior art
It is known to provide a mobile network cell in a ship for use by people who are traveling. Communication between the cell and a fixed mobile network or a land line network uses an existing communication link for the ship. An example is the existing satellite link of an aircraft. However, a problem with this approach is that there is often very limited bandwidth available over this link, and thus communication is unreliable and significant compression is required. Such links can introduce a large latency, for example a 5 second delay for a single call setup packet.
The provision of a mobile network infrastructure in remote locations is also known, being communication with the rest of the network through a satellite link. However, problems similar to those stated above apply.
Document EP 1096699 (Nokia Corporation) describes a data transmission system for communication between an MS terminal on an aircraft and a G-MSC via a satellite link.
The invention is therefore directed towards the provision of a communication system and a method for more efficient use of existing links between remote locations and a larger network infrastructure.
Summary of the invention
According to the invention, there is provided a mobile network base station controller as set out in claim 1, a mobile network cell as set out in claim 39 and a communications method as set out in claim 40.
In one embodiment, the remote communication link is a satellite link.
In one embodiment, the remote communication link is a communication link between the ship and the ground.
In one embodiment, the remote communications link is radio-based, microwave, cable, or fiber-optic terrestrial.
In one embodiment the remote gateway terminates the heartbeat signaling from the remote network nodes.
In one embodiment, the central gateway terminates the link management signaling.
In one embodiment, the central gateway terminates the heartbeat signaling from a node in the mobile network.
In one embodiment, each of the gateways dynamically chooses a suitable carrier on the remote link according to the nature of the signals to optimize bandwidth usage.
In one embodiment, each of the gateways dynamically switches between using the data and voice channels of the remote link.
In a further embodiment, the remote gateway extracts a dialed number from multiple messages, and transmits only the dialed number data from said multiple messages.
In one embodiment, the remote gateway adds additional data to the dialed number data, and the central gateway interprets the additional data to generate mobile network signals for the mobile network node.
In one embodiment, the remote gateway uses a user-to-user ISDN signaling field to transfer the additional data.
ES 2 379 786 T3
In one embodiment, the remote gateway uses DTMF to transmit the additional data and the DTMF is terminated at the central gateway.
In one embodiment, the remote gateway batch processes the location update requests according to the nature of the remote link.
In one embodiment, the remote gateway batch processes the text or multimedia messages according to the nature of the remote link.
In one embodiment, the authentication related information exchanged between the central gateway and a network node is batch processed for transmission to and from the remote gateway that handles the authentication of individual mobile subscribers.
In one embodiment, the gateways use compression for at least some internal communication over the remote link.
In one embodiment, each of the gateways stores voice packets and combines a plurality of stored voice packets into a single transmission packet.
In a further embodiment, the transmission packet is an RTP packet.
In one embodiment, the gateways perform transcoding and rate adaptation at the most appropriate gateway according to the nature of the remote link.
In one embodiment, the central gateway comprises an operations and maintenance function for both gateways.
In one embodiment, the remote gateway comprises an operations and maintenance function for itself and the remote mobile network cell.
In one embodiment, the operations and maintenance function downloads updates for the remote gateway downward.
In one embodiment the operations and maintenance function downloads fault information, status information and statistics upstream from the remote gateway.
In one embodiment, the central gateway maintains a database of the data pertaining to the remote gateways with which it communicates.
In one embodiment, the remote gateway maintains a database of registered subscribers for the remote cell.
In one embodiment, the remote gateway is linked to an entertainment or public announcement system.
In one embodiment, the remote gateway allows calls to be interrupted by the entertainment or public broadcast system.
In one embodiment the remote gateway determines whether a locally initiated call or message is for a person located in its cell, and prevents the use of the remote link if this is the case.
In one embodiment, the remote gateway is configurable to handle only text message traffic.
In one embodiment, the remote gateway rejects outgoing voice and data calls from subscribers registered in the remote mobile network cell when the system is operating in a text message only mode.
In one embodiment, the central gateway sends a signal to a registered subscriber's HLR to divert incoming calls when the system is operating in text message only mode.
In one embodiment, the central gateway detects Ocean Region changes from a remote gateway login message and from the remote ship's full address, builds a correct full dialed number including the Ocean Region that will be used to terminate voice calls to each of the subscribers.
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In a further embodiment, at least one of the gateways automatically generates a response to a network node without using the remote link.
In one embodiment, the gateway automatically generates the response within a timing period set by the network node to which it is responding.
In one embodiment, the gateway is pre-configured with rules to automatically generate such responses.
In one embodiment, said gateway is the central gateway.
In one embodiment, the central gateway automatically generates a response to an MSC class mark request.
The invention also provides a mobile network cell comprising a base station controller as defined above, and a base station transceiver.
The invention also provides a method of communication between a remote mobile network cell and a core mobile network node, the method comprising a remote cell base station transceiver communicating with a remote gateway of a remote cell controller. the base station as defined above in any embodiment, the remote gateway processing signals received from the transceiver and the transmission of the internal base station controller signals to the central gateway via the remote link.
The invention also provides a mobile station comprising an adapter for switching between a normal mode and an in-ship mode.
In one embodiment, said mobile station uses less power output for the ship mode.
In one embodiment, said mobile station automatically restricts operation to a cell on the ship in the on-ship mode.
In one embodiment, the mobile station accepts over-the-air setting of call and alert tones to silent mode.
In one embodiment, the adapter has an externally visible indicator that indicates the status of the mode.
Detailed description of the invention
Brief description of the drawings
The invention will be more clearly understood from the following description of some embodiments thereof, given only by way of example with reference to the accompanying drawings in which:
Fig. 1 is a block diagram of a communication system of the invention; and Figs. 2 and 3 are block diagrams of the central and remote gateways of the system.
Description of the achievements
Referring to Fig. 1 a communication system 1 of the invention comprises a remote part 2 and a terrestrial part 3. In this embodiment the remote part is a cell of the aircraft mobile network, however, in other embodiments it can be for a geographically remote location such as a remote town, or a ship for example. The remote party 2 comprises a conventional BTS 5 linked by a GSM link A-bis to the gateway 6 called the remote gateway. The remote gateway 6 uses the aircraft's conventional satellite communications equipment (AES) 7 and the corresponding ground equipment (GES) 8 to communicate with a central gateway 9 on the ground. The gateway 9 in turn communicates with a conventional Mobile Services Switching Center (MSC) 10. The MSC 10 may already exist as part of a Public Land Mobile Network (PLMS). The MSC 10 is linked to other nodes in your PLMN in a conventional way.
Gateways 6 and 9 are next to a BSC for the remote cell of the mobile network (in this case on the aircraft). In this way the BSC is divided into two physically separate parts, namely gateways 6 and 9. Gateways 6 and 9 use the air-to-ground link to communicate, and optimal use of bandwidth is made. available by mapping standard protocols A and A-bis over an optimized internal lightweight protocol between gateways. More flexibility is possible to internally minimize traffic within the logical BSC than would be possible on links A-bis and A on the other side of the BSC.
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The following describes an embodiment in which the network is GSM and the node being split is a BSC. However, if the network were 3G the splitter node would be an RNC, or if the network were GPRS the splitter node would be a BSC / PCU.
Conventional mobile stations 11 and 12 communicate with the BTS 5 either using a wired RF connection or a conventional wireless connection. The fact that the BSC is divided between the two gateways means that the communication from central to remote can be of very low bandwidth and in a protocol adapted for the particular circumstances. Internal traffic is minimized and optimized by the following techniques:
(a) Termination of the non-essential received signaling in each of the gateways 6 and 9, avoiding routing it between the gateways, or generating an automatic response without the use of the link. An example is the central gateway 9 that receives from an MSC a request for the class mark to determine the capabilities of the telephone set and the capabilities of the voice coding. The central gateway 9 automatically generates a reply without using the link to communicate with the remote gateway 6. The intelligence to generate the automatic reply arises from the configuration setting of the central gateway 9. This reply is transmitted within the time-out period of the MSC, so that its requirements are met. Another example is at the remote site, where a BTS and its neighbor signal strength data are measured and reported by the mobile station for handover decision to be made by the BSC. Because the remote site is inherently confined and the transfer may not be necessary, there is no need to retransmit such data, and it is simply terminated. The BTS does not wait for a response, and thus there is no timeout.
(b) Compression of voice, data, and signaling flows. In one embodiment, the RTP voice packets are stored at the gateways and combined into a single RtP packet to reduce monitoring of the packet. For example, in GSM, voice packets are sent every 20 ms. If these packets were sent in individual RTP packets the RTP header would be almost the same size as the voice payload. By combining several GSM packets in each of the RTP packets the ratio of the payload to the packet header can be significantly improved. The delay incurred by this communication process is spatially negligible when Low Earth Orbit satellites are used. Alternatively, conventional RTP header compression can be used.
(c) Carrying out GSM transcoding and rate adaptation at the most appropriate point (remote gateway 6 or central gateway 9) depending on the ship-to-ground link used.
(d) The batch processing of certain non-real-time messages such as some location update requests and SMS messages.
(e) The use of the local operations and maintenance (O&M) function on the remote gateway 6 for the configuration of the BTS 5.
(f) Optimizing the use of protocols such as X.25 reducing the packet size (in the Air - H environment this forces the MES to use an R channel instead of a T channel which improves performance).
(g) The termination of certain signaling sequences at the gateway and the transmission of essential data over the satellite link using a different protocol. For example, on A-bis, sending an SMS message involves a first A-bis message containing the text message followed by 2 confirmation messages. This procedure is executed by the gateway from the point of view of the BTS, however the text message is extracted and sent through the satellite as a single pair of X.25 packets (packet, packet confirmation). In essence, each of the gateways maps the data-rich external messages to a low-bandwidth message set that contains only the essential data. A simple example is the extraction of the dialed number from various messages on the BTS-bSc Abis interface, and the transmission of only the dialed number without the ancillary data over the satellite link. Another example is the extraction of essential encryption data from the Abis BTS-BSC interface and its transmission on a data channel of the satellite link.
(h) The dynamic choice of the satellite link channels according to the required bandwidth. For example a single Aero-H channel can be used when a voice channel is required, and if several voice calls are presented at the same time a higher capacity channel can be established (for example Swift 64) to handle these calls in a more mode cost effective.
(i) The dynamic choice of a protocol for the air-to-ground satellite link, the protocol chosen depending on the type of traffic. This feature is described later.
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Dynamic protocol selection (i)
Most satellite systems are capable of supporting several different physical interfaces and protocols. For example the Inmarsat Aero-H system supports ISDN based on circuits switched and the X.25 packet data protocol. ISDn-based circuits and their associated signaling channels are commonly used for the establishment and transport of voice calls. The X.25 channel is used to carry data pulses. The gateway will use X.25 for location update (log) and SMS traffic. Once the mobile has successfully registered on the system it can then make calls that are routed over the ISDN channel.
The establishment of these voice calls involves the gateway 6 decoding the Abis messages and mapping the contents of these messages onto the ISDN signaling channel. This ISDN signaling channel does not support the rich set of features that Abis supports and thus additional techniques are employed to transport these essential signals over the ISDN channel. Remote Gateway 6 uses the following techniques to accomplish this:
- Add extra digits to the dialed number, these extra digits are interpreted by the central gateway 9 and are used to generate the corresponding signals on interface A
- Use the user-to-user ISDN signaling field to transfer the additional data.
- By dynamically switching the circuit between data and voice call, the call could be established in the data mode and when the signaling is completed it is switched to the voice mode.
- Use DTMF to transfer the additional data, the DTMF is terminated and interpreted by the central gateway 9.
- Use a satellite sub-channel to transfer additional data.
Referring to Fig. 2 the remote gateway 6 comprises:
20: A BSC function that handles a subset of standardized BSC functionalities including adaptation and signaling switching.
21: A voice and data compression and transcoding unit that handles voice channel compression, decompression, transcoding, and rate adaptation.
22. An O&M function that handles O&M operations for the BTS 5 and the remote gateway itself 6.
23: A local maintenance terminal
24: A Local Control Panel (LCP).
25: A Subscriber Database
Referring to Fig. 3 the central gateway 9 comprises:
30: A BSC function that handles a subset of standardized BSC functionalities including signaling adaptation and switching.
31: An O&M function handles O&M operations for gateway 9, associated mobile gateways 6, and BTSs.
32: A remote gateway 6 database that is used by gateway 9 to determine the location of the BTSs in terms of communications.
33: An O&M 33 application specifically dedicated to managing the central gateway, remote gateways, and BTSs.
34: A local maintenance terminal (LTM).
35: A voice and data compression and transcoding unit that handles voice channel compression, decompression, transcoding and rate adaptation.
As the satellite links used between the aircraft and the ground station are typically low bandwidth and high cost, all unnecessary signaling is discarded or terminated by gateways 6 and 9. For example, handoffs they may not be necessary in some applications, so the measurement reports that are sent from the BTS 5 to the gateway 6 could be ignored. Other signaling messages such as heartbeat and certain O&M messages can be terminated and handled by gateway 6 or 9 in the same way that the BSC would handle these messages.
As for voice and signaling, it is necessary to minimize O&M traffic on the satellite link. The system can be configured so that only urgent fault information (alarms) will be relayed immediately to the ground station. Other non-urgent failure indications are logged to remote gateway 6 which can generate an immediate alarm to the ground station if the arrival rate of these minor failure indications exceeds a threshold. The severity of the alarm and the threshold values associated with this behavior are configurable.
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For aircraft applications, the ship-to-ground link is based on commercial satellite systems such as Inmarsat, Intelsat or ground systems such as NATS or microwaves. Different satellite systems vary greatly in bandwidth and quality. The satellite modules on the spacecraft (Earth Station of the
Aircraft or Mobile Ground Station) exhibit many different interfaces such as ARINC 746 used in aeronautical applications and IP or Frame Relay used mainly in the maritime industry.
Gateways 6 and 9 are capable of handling these different interfaces and systems both in terms of physical interfaces and protocols. In addition, the functional partition between gateways 6 and 9 can be configured to optimize the use of the satellite link. GSM transcoding and rate adaptation (TRAU) can thus be performed either on board the ship via gateway 6 or on the ground via gateway 9.
For example, in the case of Inmarsat Aero-H, the transcoding is done on the ship by gateway 6. This is because the Aero-H module that supports a PCM E1 CEPT link, compresses the voice signals itself. before sending them over the satellite link.
In a typical maritime example, a transparent IP link is available between gateways 6 and 9. In this scenario, GSM encoded TRAU frames could be transported over the IP link using a direct transmission protocol such as RTP. . Alternatively, if the GSM encoding is not efficient enough for the satellite link in question, the transcoding can be performed by the gateway 6 which then uses a more efficient compression algorithm before transmission to the satellite module.
The local maintenance terminal 23 of the remote gateway 6 supports functions used by field personnel including, but not limited to the following:
• Reading the fault information • Reading the log files • Downloading down statistics • Configure the BTS and the gateway 6.
• Up-download of new software versions to BTS and Gateway 6.
• Check that BTS and Gateway 6 are working properly.
The LMT 23 is not required for the normal operation of the BTS 5 or the 6/9 gateway which can be remotely maintained from the ground-based OMC.
The Local Control Panel 24 allows the crew to enable and disable the system and set the service. The Local Control Panel 24 also gives the crew system status and fault indications.
The signaling from the BTS 5 is carried in an optimized format over the satellite link. The BSC function in the central gateway 9 adapts this signaling to the standard A-interface format before sending it to the MSC. The BSC function terminates unnecessary traffic from the MSC and simulates the traffic from the BTS such as the heartbeats that the MSC needs to receive.
To establish a connection with a remote gateway 6, the central gateway 9 must know the location and environment of the remote gateway 6 so that the appropriate communication channel can be established. This information is kept in database 32. This keeps a record of which remote gateways are currently active and have logged into the system. This database also maintains a list of mobiles that connect to each of its BTS 5. This is to allow implicit deregistration of these mobiles when the BTS 5 and / or gateway 6 become unreachable. The subset of the database 32 containing information corresponding to the particular gateway 6 is also stored in the subscriber database 25 on that gateway 6. This allows the gateway 6 to take into account subscriber data such as class of service when processing calls over the ship.
The O&M function 31 in the gateway 9 is responsible for the management of the gateway 9, the gateway 6, and the BTSs. It handles the O&M data (faults, statistics and configuration) exchanged with the air transport BTS and Gateway 6 over the satellite link. The OMC downloads software and configuration data upstream to Gateway 6 to allow online update for BTS 5 and Gateway 6. The O&M function 31 communicates with a OMC 40 using SNMP and with the OMC of the gateway 33 using an appropriate protocol.
The following describes the operation of the communication system of the invention in more detail. This can be divided into eight major areas, viz.
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BTS and Gateway Login
Logout of BTS and Gateway
Location Update
Highlight IMSI
Mobile Originated Voice Call Mobile Terminated Voice Call Mobile Originated SMS Mobile Terminated SMS
Taking each one in turn
BTS and Gateway Login
Once the ship has reached an appropriate location, the system on the ship is started either automatically or manually by the crew. The gateway 6 verifies that the ship-to-ground module has already logged into the ground station and then sends a login message to the gateway 9 containing its identity and authentication information.
Gateway 6 communicates with other on-board systems to determine operational parameters such as location, altitude, and status of the ship. This equipment includes but is not limited to the following:
- ARINC 429 or ECL ARINC 746 bus for location and altitude.
- Various discreet signals for the status of Weight on Wheels, status of seat belts and status of open doors.
- GPS system for locating the ship.
- Local Control Panel.
The gateway 9 updates the database 32 with the identity of the gateway 6 and relevant data for the communication channel. Contrary to the ground-based GSM network where the BTS sites are wired to a particular BSC, in the invention the different dynamically assigned communication channels can be used to connect a gateway 6 to the gateway 9. The gateway 9 must therefore keep track of the location of the gateway 6 and the communications environment.
The gateway 9 maintains the associations between the identity of the ship (eg an AES id of the aircraft) and the location areas (LA) known to the MSC 10 in the database 32. The MSC 10 will page the subscribers in a particular Location Area and the gateway 9 will use this association and its knowledge of the registered subscribers on each of the remote gateways to locate the gateway 6 on the ship to relay. the paging message to the correct BTS 5.
For example, Inmarsat uses four geostationary satellites to achieve close to full coverage, only the Polar regions are not covered. To communicate with an aircraft, the gateway 9 must know which of the four ocean regions the aircraft is flying over and therefore which satellite to use. Gateway 6 polls the SatCom module regularly to see if the satellite receiver has logged on to a new satellite. This occurs when an aircraft passes from one satellite to another. If the Ocean Region has changed, gateway 6 starts a new login procedure (in this case the BTS stays online so mobiles are not required to register) and gateway 9 updates the database 32 with the new information of the area. Alternatively, the gateway 9 can recognize that the spacecraft has changed satellite and establish a link through the new satellite without the need for a login procedure.
Gateway 9 will detect Ocean Region changes from the login message. From the full addresses (for example X.25, E.164, Inmarsat number, IP, etc.) of the remote ship build the complete correct dialed number (including ocean region) that will be used to terminate calls from voice for each of the subscribers. The dialed number is a combination of the ocean region, the ship number, and the seat number. Each subscriber will be assigned a number for the duration of the flight. When the gateway 6 detects an incoming call on a particular number it will match that number with a subscriber to terminate the voice call.
Logging out of the BTS and the gateway
Gateway 6 can be closed either automatically (eg, when the ship approaches a specific geographic location) or manually by the crew. When this occurs, the gateway 6 sends a logout message to the gateway 9 which updates the database 32 and sends a disconnect message to the MSC for all subscribers that were registered with the BTS.
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Location update
When a mobile on the ship loses signal from the ground, the PLMN will scan for a new network and find the BTS Broadcast Control Channel (BCCH) on the ship. Once hooked to this new BCCH, the mobile recognizes that the location area (and the PLMN) has changed and thus will perform a location update procedure.
In another embodiment, specially adapted mobile stations 12 will begin searching an aircraft network as soon as they are put into aircraft mode.
The mobile uses the Random Access Channel (RACH) to gain access to the BTS 5 and request a signaling channel.
The BTS relays the request to gateway 6 which responds with a channel assignment command to the BTS. The BTS in turn instructs the mobile to switch to the assigned channel.
Once the mobile has switched to the signaling channel, it sends a location update request to the BTS which relays the request to gateway 6. Gateway 6 establishes a connection with gateway 9 (if not one has already been established) and uses this connection to forward the request to the MSC.
The MSC responds by sending an authentication request to the mobile which is again relayed to the BTS and the mobile through the gateways and the data connection.
The mobile device processes the authentication request and sends the response back to the MSC. The MSC checks the response and, if successful, updates the VLR and HLR.
The MSC then instructs Gateway 9 (BSC) to clear the call. Gateway 6 sends the delete command to the mobile. Once confirmed by the mobile, the gateway 6 can drop the data connection.
In another embodiment, Location Update requests from mobile devices are immediately acknowledged by gateway 6. These requests are then stored at gateway 6 until a relevant request threshold is exceeded or a timer expires, The requests are then processed in batches and sent to Gateway 9. The gateway 9 then sends the location update requests to the HLR and obtains authentication triplets from the HLR for each of the mobile stations. The triplets are batch processed and sent to gateway 6 which will use these triplets to authenticate mobile stations before they are allowed to initiate or receive service requests. This mechanism makes the use of the signaling channel more efficient while ensuring that mobile stations are correctly authenticated.
If, for any reason, the location update and / or authentication procedures fail, the registration request from the mobile will continue to be confirmed. This ensures that the mobile remains camped in the on-board cell and its power can be controlled by the gateway 6. Service requests to and from these mobiles will be rejected by the system until the location and location update procedures. authentication have been completed successfully.
Known subscribers can be included in different classes. The system can be configured to restrict access and service to certain classes of subscribers. For example, in a given configuration first class and business class subscribers can be allowed to make and receive voice calls while economy class passengers are only allowed to send and receive SMS messages.
IMSI Separation
The IMSI separation procedure starts when the mobile is turned off. A detach message is sent over the satellite link to the ground-based MSC. The MSC updates the subscriber's HLR so that new calls to the subscriber will end at the local PLMN (typically diverted to voicemail) and will not use satellite resources unnecessarily.
If the ground station loses contact with the air transport gateway, it will initiate an automatic detachment procedure (implicit deregistration) after a configurable time for all subscribers who have logged into the corresponding BTS.
Voice call originated from a mobile
Once the mobile has successfully registered on the network, it can make an outgoing call. The air interface used is the normalized GSM so that the mobile does not see any difference between the BTS of the transport
ES 2 379 786 T3 air and ground BTS.
The mobile uses the Random Access Channel (RACH) to access the BTS and request a signaling channel.
The BTS relays the request to the gateway 6 which responds to a channel activation command for the BTS, the BTS activates a signaling channel (SDCCH). The gateway 6 now sends an Immediate Assignment Command to the BTS which is relayed to the mobile over the Access Grant Channel (AGCH). The mobile switches to the SDCCH and sends a CM Service Request for a Mobile Originated call. Gateway 6 replies with an acceptance message and the mobile accepts a Set-up message containing the dialed digits.
Gateway 6 uses these digits to construct and send an ARINC 746 setup message to the SatCom / NATS module. This setup message is routed through the satellite network to the GES on the ground. The GES relays the setup request to the gateway 9, the gateway 9 uses the contents of the setup message to construct and send a setup message of the standard A-interface to the MSC.
The MSC routes the call to the called party.
Gateway 6 now instructs the BTS to activate a traffic channel (TCH). The gateway 6 sends an Immediate Assignment command through the BTS to the mobile which switches to the traffic channel. Gateway 6 instructs the BTS to release the signaling channel (SDCCH).
Once the called party has been located over the PTSN, an alert message is sent over the PSTN via the MSC, Gateway 9, GES, and SatCom / NATS to Gateway 6.
The gateway 6 relays this Alert message through the BTS to the mobile. The user now hears the ringtone.
When the called party goes off-hook, a Connect message is sent over the PSTN through the MSC, gateway 9, GES, and SatCom / NATS to gateway 6.
The gateway 6 relays this Connect message through the BTS to the mobile. The call is now established.
The gateway supports an external interface to the ship's In-Flight Entertainment system or Public Broadcasting system. The gateway 6 recognizes when the IFE or PA system needs to make a voice broadcast to the passengers and overlays the broadcast of the crew on the audio signal of the call. This allows the crew to interrupt calls for important messages.
In another embodiment, if the gateway 6 recognizes that the receiver is registered on the same ship the call can be switched locally at the gateway. This is to prevent unnecessary use of the ship-to-shore link bandwidth when both calling and called parties are logged into the same gateway 6. This local switching feature can be enabled or disabled by class of subscriber.
Voice call terminated on mobile
The MSC determines the location area of the called mobile and sends a paging message to the gateway 9 (BSC). Gateway 9 immediately responds to the MSC and the MSC sends a setup request. In this case, each of the location areas is associated with one or more mobile gateways 6. The gateway 9 queries the database 32 to find the ocean region and consequently the correct satellite to use for communications with the BTS.
The gateway 9 uses the setup request from the MSC to construct and send a setup request to the mobile via the GES. This causes an ARINC 746 Establishment request to be generated on the SatCom / NATS module and sent to gateway 6.
Gateway 6 uses the information in the Setup message to build a Paging Command and send it to the BTS.
The BTS pages the mobile on the Paging channel (PCH). The mobile responds with a Channel Required message on the Random Access Channel (RACH).
The BTS relays the Channel Required request to the gateway 6 which responds with a channel activation command to the BTS, the BTS activates a signaling channel (SDCCH). Gateway 6 now sends an Immediate Assignment Command to the BTS which is redirected to the mobile over the Access Grant Channel
ES 2 379 786 T3 (AGCH). The mobile switches to the SDCCH and sends a Paging Response through the BTS to the gateway
6.
The gateway 6 sends an ARINC Call Procedure message 746 to the MSC via the satellite link, GES and gateway 9.
The gateway 6 sends a setup message through the BTS to the mobile which responds with a Call Confirmed message.
Gateway 6 again instructs the BTS to activate a traffic channel (TCH). The gateway 6 sends an Immediate Assignment command through the BTS to the mobile which switches to the traffic channel. Gateway 6 instructs the BTS to release the signaling channel (SDCCH).
The mobile starts the ringing signal and sends an Alert message to gateway 6.
When the subscriber goes off-hook a Connect message is sent through the BTS to gateway 6, gateway 6 uses this message to construct an ARINC Connect message 746 which is sent to the SatCom / NATS module.
Gateway 9 relays this Connect message to the MSC. The call is now established.
Mobile originated SMS
Once the mobile has successfully registered on the network, it can send an SMS message. The air interface used is the normalized GSM so that the mobile does not see any difference between the air transport BTS and the normal land BTS.
The mobile uses the Random Access Channel (RACH) to access the BTS and request a signaling channel.
The BTS relays the request to the gateway 6 which responds with a channel assignment command to the BTS. The BTS in turn instructs the mobile to switch to the assigned channel (SDCCH).
Once the mobile has switched to the signaling channel, it sends an SMS request to the BTS which relays the request to gateway 6. Gateway 6 establishes an X.25 circuit (if it was not already established) and use this circuit to relay the request to the MSC.
The MSC relays the SMS request to the subscriber's local SMSC which handles the sending of the message to the receiver.
In another embodiment, if the gateway 6 recognizes that the receiver is registered on the same ship, the SMS message can be switched locally at the gateway. This is to eliminate unnecessary bandwidth usage of the ship-to-ground link when both the transmitter and receiver are logged into the same gateway 6.
SMS terminated on mobile
The MSC determines the location area of the called mobile and sends a paging message to the gateway 9 (BSC). In this case each location area will have a single cell / bTs. The gateway 9 requests the Mobile Gateway Database to find the ocean region and consequently the correct satellite to use for communications with the BTS.
Gateway 9 establishes an X.25 circuit with the air transport gateway (if not already available) that is used to relay the paging message to the BTS. BTS pages the mobile.
When the mobile detects the page it will immediately request a channel. The gateway 6 assigns a signaling channel to the mobile which sends a paging response to the MSC on this channel.
The MSC now sends the SMS to the receiving mobile through the gateway 9, the X.25 satellite link, the gateway 6 and the BTS respectively.
The gateway 6 can send SMS messages to any mobile station registered on the ship. This facility is typically used to broadcast information such as welcome messages to all registered users. These messages can be sent automatically or when requested by the crew. The provision of these internal SMS messages and the SMS messages within the ship do not require any communication between the ship and the ground.
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The conventional Pico BTS existing on the market today constitute small and economically viable practical elements for GSM solutions in Air Transport. However, the alternative elements of the bSc network available on the market do not meet the strict restrictions of this particular market segment. If a product were marketed that would thus satisfy such constraints, the global network architecture of a ground-based MSC communicating with thousands of individual BSSs would not be viable. There are several significant technical restrictions for just such BTS and BSS, on the aircraft.
The Distributed BSC Architecture, consisting of ground-based Gateways, each supporting one or many Mobile Gateways on board, supports the standardized GSM A and A-bis interfaces. This allows the use of unmodified standard components from BTS and NSS off the platform which significantly reduces the cost of the system. Furthermore, the one-to-many relationship between Fixed Gateway and Mobile Gates minimizes the number of expensive signaling links required in the NSS for a given mobile population, further reducing cost.
Efficient use of satellite bandwidth is achieved through the Call Handling Model and the Signaling Coding Scheme.
The call model can make use of raw satellite bandwidth or can be supported on existing ISDN-based systems (Q.931), whichever is more appropriate; this allows the use of existing satellite equipment in a more cost effective method. The data streams carrying voice traffic are compressed to ensure optimal cost for a quality ratio.
The signaling coding and handling scheme ensure that the system uses the lowest possible satellite bandwidth while supporting all the signaling necessary for compatibility with PLMN requirements such as mobile authentication. All unnecessary signaling is terminated at the central gateway 9 and remote gateway 6 so that only profit-generating calls, relating to signaling and essential mobility management signaling, occupy satellite bandwidth. In the absence of call traffic and mobility management traffic, no satellite bandwidth is used.
In other embodiments, the BTS could support other radio protocols including but not limited to the following:
CDMA (IS95) and CDMA evolutions (CDMA 2000, CDMA 20001X, etc.)
UMTS and UMTS evolutions
GSM evolutions such as GPRS, HSCSD, EDGE
TDMA
TD-SCDMA
Wireless LAN, RFC 802.11
Bluetooth
In another example the communication systems between the spacecraft and the ground could use other satellite-based or terrestrial systems such as NATS, TFTS, Microwave, Intelsat, Globalstar, Iridium, ICO, connection by Boeing or other Inmarsat systems. Also remote parties can alternatively be located in a fixed location, for example by providing a small GSM facility in a remote fixed location such as a remote town or regions where there is generally poor mobile network infrastructure. Although the invention as described splits a BSC into two gateways, it can instead divide an equivalent mobile network node such as an RNC for a 3G network, or PCU for a GPRS network.
In another aspect, specially adapted mobile stations can be used at the remote end. This adapted mobile is intended for use in an aircraft where there is a risk or perceived risk of interference with on-board avionics equipment. This adapted mobile station supports the following features in addition to the standard GSM features:
- The mobile station has an external switch and an indicator used to put the mobile in aircraft mode. The position of the switch and the indicator are externally visible so that they can be checked by the crew members.
- When in aircraft mode, the mobile station will automatically limit its output power to a predefined value, typically on the order of 20 mW.
- When in aircraft mode, the mobile station will only log into the aircraft networks. The type of network (normal or aircraft) is indicated in the Broadcast Control Channel (BCCH) of the air transport BTS. For emergency calls, the mobile station can register on any BTS.
- When in aircraft mode, the mobile station will accept the Over the Air (OTA) setting of call and alert tones to silent mode using SMS. This is to minimize inconvenience to other passengers.
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The BTS 5 and the gateway 6 are capable of handling both conventional mobile stations and adapted mobiles as described above.
Contents13
3 sheets
Sheet 1 Sheet 2 Sheet 3
8 members in 5 offices
Priority claims3
| Document | Office | Kind | Date |
|---|---|---|---|
| 499010P | United States of America | – | |
| 49901003 | United States of America | P | |
| 2004000114 | Ireland | W |
Members8
| Document | Office | Kind | |
|---|---|---|---|
| WO2005022779A1 | World Intellectual Property Organization (WIPO) | A1 | |
| EP1661265A1 | European Patent Office (EPO) | A1 | |
| US2006154660A1 | United States of America | A1 | |
| US7783288B2 | United States of America | B2 | |
| EP1661265B1 | European Patent Office (EPO) | B1 | |
| AT545217T | Austria | T | |
| ATE545217T1 | Austria | T1 | |
| ES2379786T3This record | Spain | T3 |
Numbers
- Publication
- 2379786
- Application
- 4770389
Titles2
- Spanish
- Un sistema y un método de comunicaciones
- English
- A system and method of communications
Classification
- CPC, 10
- H04B7/18558
- H04B7/18508
- H04B7/18569
- H04W12/06
- H04W60/00
- H04W84/005
- H04W84/04
- H04W84/06
- H04W88/08
- H04W88/12
- IPC, 8
- H04B7 185
- H04W88 08
- H04W88 12
- H04W12 06
- H04W84 04
- H04W84 06
- H04W60 00
- H04W84 00