KR100888160B1 - Communication network and method - Google Patents

Abstract

The present invention relates to a wireless, ad-hoc or private communications network 100, wherein the network 100, together with other elements of the network, forms nodes 102, 112 that form a switching and management infrastructure (SwMI). 120, 130, 140) and subscribers; Each of the nodes 102, 112, 120, 130, 140 has a visitor location register (VLR) 108, 118, 126, 136, 142, and of the nodes 102, 112, 120, 130. At least some have home location registers (HLRs) 106, 116, 124, 134, and at least some of the nodes 102, 120 with the HLRs 106, 124 are gateways 110, 128. All nodes 102, 112, 120, 130 with HLRs 106, 116, 124, 134 are assigned to nodes 102, 120 with gateways 110, 128, and the SwMI Send calls to and from subscribers of network 100 through the assigned node with a gateway to an external network.

Private Communication Networks, Home Location Registers, Gateways, Nodes, External Networks

Description

Communication network and method

The present invention relates to a communication network and method for managing services to or from external networks, in particular ad-hoc or private communication networks based on TETRA (Terrestrial Trunked RAdio) cellular communication system. .

In cellular communication systems (such as pan-European mobile communications (GSM) and TETRA (terrestrial public communications)), the geographic area is divided into a plurality of cells, each of which is served by a base station. One base station, called a base transceiver station (BTS) with a switching infrastructure, is referred to as a node of the network. The switching infrastructure that supports BTS can be shared with other BTSs. The system infrastructure in a TETRA system is generally referred to as a switching and management infrastructure (SwMI) that includes substantially all communication elements located away from MSs. This includes base transceiver stations (BTS) connected to a conventional public switched telephone network (PSTN) via base station controllers (BSC) and mobile switching centers (MSC). In geographic terms, the reference for a node is a reference for the area serviced by one BTS, and in network terms, the reference for a node is a reference for the infrastructure equipment needed to support one or more BTSs. The remote unit, referred to as the subscriber or mobile station (MS) or communication unit, is serviced via a wireless communication link by the base station of the cell in which the remote unit is operating.

One of the basic advantages of cellular communication systems is that the subscriber can move from one geographic location to another while receiving services from the network. There are ranges of overlapping coverage between base stations to provide seamless service. When the subscriber moves from the area served by the first base station to the area served by the second base station, the subscriber enters a range of overlapping coverage. Within the scope of overlap coverage, the subscriber changes the serving base station. This is known as cell reselection or handover.

The communication link from the BTS to the subscriber is generally referred to as the downlink communication channel. Conversely, the communication link from the subscriber to the BTS is generally referred to as an up-link communication channel.

In order to perform communication between two handsets operating in two different cells, the fixed network interconnects the base stations. The fixed network is operable to route data between any two base stations, and this method allows for communication between these two remote handsets. Moreover, the fixed network may include gateway functions for interconnecting external networks such as a public switched network (PSTN). This allows subscribers to communicate with landline telephones and other communication terminals connected by the landline. In addition, the fixed network is adapted to perform the functions necessary to manage conventional cellular communication networks including data routing, admission control, resource allocation, subscriber charging, mobile station authentication, and the like.

The TETRA communication system can be used as a public cellular communication system. However, the main application of TETRA communication systems is the use by organizations or groups, such as emergency services. Certain functions and services implemented in the TETRA system make the system particularly suitable for services such as police, emergency, fire and lifesaving. One of these features provided by the TETRA system, which is particularly useful for emergency services, not only controls group calls but also manages the membership of these groups. Other features and services provided by TETRA include push-to-talk channel allocation, broadcast calls, and the like. In addition to relay mode operation, in which remote units communicate with the base station, TETRA offers the possibility to communicate directly between remote units without the involvement of infrastructure. This is known as direct mode of operation (DMO).

A deployable or ad-hoc network may be considered as a network in which the number of nodes that together provide services to mobile users and the topology of the network vary from time to time. Connections between these nodes change in number and shape over time with or without the change of nodes. Nodes can be added or removed. Some nodes may provide gateway services and others may not provide such services. The gateway services available at the nodes may also change from time to time, such that at any one time a node can provide the services and at other times the services cannot be available.

In such a deployable or ad-hoc mobile network where a user needs to access services from outside the network via gateways, which gateway must be accessed by the user and which gateway can send calls from outside the network to send to the user. Or it may be difficult to determine if other information should be received. It may also be difficult to set up group services at high speed, especially in a true ad hoc network. When calls are sent directly to users via gateways, it is expected that calls will be received at the gateway with a connection to the home location register (HLR). This is because the HLR of the user obtains information from the node from which the user currently obtains the service. In an ad hoc network, the connection between any one gateway and the user's HLR cannot be guaranteed. Calls originating from users may need to be routed to specific gateways. It may be difficult to identify a particular gateway in an ad hoc network. Gateways may not have external connections available or have external connections available, depending on the state of the network. If the mobile users or their HLRs are completely distributed, it is unclear whether the node to which the mobile user is connected has an available connection or whether the node to which the HLR is connected has a connection, It makes it difficult to determine how to route.

Thus, there is a method in which the location information of subscribers in a communication network and the nodes that are in which gateways are deployed, in particular when the network is required to operate independently of the reconfiguration processes, can be mitigated or overcome. need.

Accordingly, the present invention preferably alleviates, alleviates or eliminates the aforementioned disadvantages, alone or in any combination.

According to a first aspect of the invention, there is provided a wireless, ad-hoc or private communication network as claimed in claim 1.

According to a second aspect of the invention there is provided a method for managing services from or to external communication networks in an ad-hoc or private communication network as claimed in claim 16.

The invention advantageously,

Transparent access to services outside the deployable or ad-hoc mobile network via gateways,

Determine gateways suitable for conducting calls between mobile users and fixed network gateways,

Determine a gateway suitable for receiving calls or other information from outside the network for transmission to the user.

The invention will be more fully understood from the following detailed description set forth in connection with the drawings.

1 illustrates a communication network according to an embodiment of the present invention.

2 is a flow chart illustrating a method of managing services from or to external communication networks in an ad-hoc or private communication network in accordance with an embodiment of the present invention.

The term "home location register" (HLR), described below, refers to a database containing configuration information and location information related to all subscriber homes for a particular node or nodes. One HLR may cover more than one node.

The term "Visitor Location Register" (VLR) described below refers to a database containing information about subscribers operating at a particular node and refers to the respective HLRs (ie, HLRs that are home to the subscribers listed in the VLR). Keep pointers to. Every node in the network has been assigned a separate VLR.

The term "look-up table" described below refers to a table that is copied to all nodes and used to allocate individual and group address spaces between nodes. It may act as a set of individual entries for each individual user or group, for example arranged as a list, where each entry includes a reference to a node where information about the individual or group is stored. This can simplify the list by grouping identifiers together, for example by dividing the address space into blocks of numbers and then assigning each block to one of the nodes, i.e., obtaining the correct HLR for each block of identifiers. Can be identified. When all nodes have the same look-up table, if a subscriber (or group member) registers with any node, the node can immediately know which node contains the HLR for the subscriber (or group).

The following discussion focuses on embodiments of the present invention applicable to TETRA cellular communication systems. However, it should be appreciated that the present invention is not limited to this application and can be applied to many other communication systems (eg, APCO Project 25 or GSM and other digital and analog communication systems).

Referring to FIG. 1, one embodiment of the present invention depicts a wireless, ad-hoc or private communications network 100 (hereinafter referred to as a network). Network 100 includes a plurality of nodes 102, 112, 120, 130, 140 that form a switching and management infrastructure (SwMI) along with other elements of the network. Each of the nodes 102, 112, 120, 130, 140 has a visitor location register (VLR) 108, 118, 126, 136, 142, respectively. Each of the nodes has a copy of the look-up table 104 indicating the assignment of subscribers to HLRs. At least some of the nodes 102, 112, 120, 130 have home location registers (HLRs) 106, 116, 124, 134, and at least some of the nodes with the HLRs have gateways 110, 128). Every node with an HLR is assigned to a node with a gateway. As a result of the assignment, the SwMI sends all calls to and from the subscriber through the assigned gateway. If a first subscriber whose data is stored in a third HLR 116 requests a call to an external network, the SwMI may then turn the first gateway 110 when the third node 112 is assigned to the first node 102. Send the call through.

According to one embodiment of the invention, the assignment of identifiers to the nodes is such that individuals at the nodes 102, 120 where the gateways 110, 128 are located are assigned only to the HLRs 106, 124. In one embodiment, the external network (s) to which the network 100 is connected from the look-up table 104 or the look-up table 104 to identify nodes whose data about a particular subscriber are included in the HLR. Has a subset of the data. Once the call is routed from the external network to the user, the external network is either the first gateway 110 or the second deployed at the first and second nodes 102 or 120, respectively, where an HLR containing the subscriber's information is deployed. It will have the information needed to transfer the call to the gateway 128. The network 100 may then route the call to the subscriber when the HLR includes information indicated by the node where the subscriber is currently located.

According to another embodiment of the present invention, nodes that have gateways but are not connected to an external network may be identified. In this case, subscribers are not assigned to HLRs at these nodes, but are only assigned to HLRs at nodes where gateways have a connection to an external network.

According to another embodiment of the invention, the subscriber's data may be included in the HLRs 106, 116, 124, 134 deployed in any of the nodes regardless of whether the node owns the gateway. Each of the HLRs 106, 116, 124, 134 includes a reference to the nodes 102, 120 where the gateways 110, 128 are located. If the gateway is arranged with the HLR, as in the case of the first HLR 106 and the first gateway 110, the reference in the HLR will often be for a gateway located at the same node, for example the first HLR 106 has a reference to the first gateway 110, but this need not be the case.

Gateways also include a reference to HLRs that are associated by previous criteria for these gateways. As described above, if the HLR 106 has a reference to the gateway 128 rather than the gateway 110 (eg, in a situation when the gateway 110 is not connected or operable to an external network). The previous reference of the HLR 116 pointing to the original gateway 110 is redirected to point to the gateway 128.

The external network has information representing the appropriate gateway for each subscriber or group. In this way, when a call is made from an external network to a subscriber or group, the external network identifies the correct gateway 110 or 128 that routes the call; Once the call is received by the gateway, the gateway can search each of its reference HLRs to find the actual HLR containing the data of individual subscribers or groups and thus restore location information for routing the call. Routing of calls within the network may be made directly by the gateway when receiving routing information from the HLR or by sending the call to a node where the subscriber or group's HLR is deployed, which node may be the subscriber or the group. Send calls in turn.

It can also be seen that this embodiment also considers the case where not all gateways have access to the external network. HLRs include criteria for gateways having connections to an external network, which gateways have corresponding criteria for all HLRs.

It can be seen that the criteria between the HLRs and the gateways can be unusual in that only one HLR refers to one gateway and only the gateway refers to any one HLR. However, in other embodiments, the criteria are not peculiar, and if each gateway 110, 128 is placed at a node where a copy of the look-up table 104 is located, calls from the external network are directed to the subscriber or group. Since the correct HLR can be easily identified, it can be routed to subscribers or groups.

In one embodiment of the present invention, the configuration of the table 104 may be made by manual methods or by configuration from an application.

In another embodiment of the invention, the assignment of nodes to nodes with gateways is controlled by an external network. In this embodiment, the configuration of the table 104 is made by an external network, which may determine which gateways are best suited for routing scheduled calls to subscribers or groups of the ad hoc network 100. .

In another embodiment of the present invention, the nodes 102, 112, 120, 130, 140 are suitable for searching for a node having a gateway. The purpose of this discovery is to assign HLRs to the first 102 and second 120 nodes having the first and second gateways 110 and 128, respectively. Once the node with the gateway has been found by the discovery process, the HLR can record the criteria for this node with the gateway and provide the gateway with the corresponding criteria for the HLR. Thus, as an example, the third node 112 can identify the first node 102 by performing a search and having an appropriate first gateway 110 and can store the criteria for the first node 102. And provide a reference to itself (ie, the third HLR 116) to the first gateway 110.

The discovery process may be external such as the lowest number of connection links between the node and the identified gateway, the lowest cost routes between the node and the identified gateway, gateways with any bandwidth or service capabilities, service, connection cost and other such parameters. Gateways with any connection feature to networks, or any combination thereof, may include known techniques that provide the desired features to the criteria for gateways.

The search may identify gateways that do not have external network connections and may reject them by gateways 110 and 128 with external connections.

The search may generate unique relationships between nodes that include HLRs and a node that includes gateways, or may generate multiple relationships.

The search may be initiated by manual operation or may be initiated by any other event, such as a change in the gateway state of a connection to an external network, which change may include a change in service characteristics. Discovery caused by the change of features can minimize the inactivity of the existing gateway. This search may be performed by all nodes in the network with HLR or by nodes with references to the gateway whose features are to be changed. The search may be performed by a search algorithm implemented in software running on the nodes 102, 112, 120, 130, 140.

As a result of a search for the network or a manually initiated update, the subscriber's information contained in one HLR may be moved to another HLR. For example, if the first gateway 110 located at the first node 102 is separated or removed from the external network, the subscriber's information contained in the first HLR 106 may be connected to the connected second gateway 128. The branches may be sent to the second HLR 124 disposed in the second node 120. The look-up table 104, which describes the assignment of subscribers to HLRs, will also be updated. Optionally, the HLR data may be maintained at the HLR at the same node, but the criteria are updated, such that the first HLR 106 is for example detached or removed from the first gateway 110 deployed at the first node 102. In this case, reference may be made to the second node 120 having the second gateway 128.

The complete node may be separated from the network 100. Individual subscriber and group data of an HLR associated with such a node may be moved to another HLR in accordance with British Patent Application No. 0409473.6. For example, if the first node 102 is removed from the network 100, the subscriber's data included in the first HLR 106 disposed in the first node 102 may include a second gateway 128. May be moved to a second HLR 124 disposed at node 120. Network 100 is updated with a new location of data previously stored in first HLR 106 to fully operate all VLRs 108, 118, 126, 136, 142 in network 100. Otherwise, they point to HLR that does not exist.

Similarly, reconfiguration of network 100 and transmission of first HLR 106 to second node 120 modifies the structure of look-up table 104 of network 100. The look-up table 104 at the nodes of the network 100 is updated with information from which records from the first HLR 106 are sent.

Optionally, the subscriber's data may be placed in a third HLR 116 of a third node 112 where no other HLR is located, such as via a second gateway 128. Criteria may be given for a second gateway 128 disposed in the second node 120 to be accessible to and from subscribers from an external network.

In one embodiment, the configuration of the subscribers in the HLRs 106, 116, 124, 134 or the assignment of the subscribers in the HLRs 106, 116, 124, 134 may include the nodes 102, 112, 120, 130. Is provided to the external network, whereby the external network always provides calls to the mobile network through the gateway with assignment to the HLR where the subscriber record is maintained.

If an individual subscriber or group does not require services using a gateway, the subscriber's HLR entry may be made at any suitable node in the network. Typically, this may be in a node close to the normal location of an individual subscriber or group.

Referring to FIG. 2, a method for managing services from or to an external communication network in an ad-hoc or private communication network 100 is described. Each node 102, 112, 120, 130 of the network 100 having an HLR performs a search for a node having a gateway 110, 128 (202). When nodes 102 and 120 with gateways 110 and 128 are found, the HLR from the node performing the search is assigned to the node with the gateway (204). If more than one node with a gate is found, the nodes are the lowest number of connection links between the node and the identified gateway, the lowest cost routes between the node and the identified gateway, gateways with any bandwidth or service capabilities, service, Select gateways with any desired characteristics, such as connection cost and other parameters, with any connection characteristics to external networks, or any combination thereof.

In one embodiment, if a third node 112 without a gateway is assigned to a first node 102 with a gateway and the first node is reconfigured (206), HLRs 204 assigned to the first node. Is transmitted to another node having a gateway (208). In one embodiment, the records of the HLR sent to the first node 102 are fused with the records of the first HLR 106. In another embodiment, the records of the HLR transmitted to the first node 102 are the first node 102 as a separate HLR in addition to the first HLR 106 assigned to the first node 102 prior to the transmission. Is assigned to. This solution is particularly advantageous when the node is temporarily disconnected from the network 100 (which facilitates retransmission).

Optionally, instead of sending HLRs, the criteria in each HLRs are updated to point to a node with a gateway.

Claims (12)

As an ad-hoc network 100, The ad 100 includes a plurality of nodes 102, 112, 120, 130, 140 and a plurality of subscribers forming a switching and management infrastructure (SwMI) with other elements of the network. in the hoc network 100, Each of the nodes 102, 112, 120, 130, 140 has a visitor location register (VLR) 108, 118, 126, 136, 142, of which nodes 102, 112, 120, 130. At least some have home location registers (HLRs) 106, 116, 124, 134, and at least some of the nodes 102, 120 with the HLRs 106, 124 are gateways 110, 128. )To have, All nodes 102, 112, 120, 130 with HLRs 106, 116, 124, 134 are assigned to nodes 102, 120 with gateways 110, 128, and the SwMI is assigned with the gateway. Ad-hoc network (100), characterized in that it is adapted to direct all calls to subscribers of the network (100) and all calls from subscribers to an external network via a connected node. The method of claim 1, The nodes are adapted to perform the assignment to the node with a gateway if the assignment is performed as a result of a) predefined, b) controlled by an external network, or c) searching for a node with a gateway. Ad-hoc network 100. The method of claim 2, The first node 102 with the first gateway 110 may be configured such that a) the first gateway 110 is not available or b) the characteristics of the first gateway 110 are changed. Ad-hoc network (100), adapted to transmit data from a first HLR (106) belonging to (102) to a second node (120) having a second gateway (128). The method of claim 2, The first node 102 with the first gateway 110 may be configured such that a) the first gateway 110 is not available or b) the characteristics of the first gateway 110 are changed. An ad-hoc network (100), adapted to generate a reference from a first HLR (106) belonging to (102) to a second node (120) having a second gateway (128). The method of claim 4, wherein At least one of the HLRs (106, 116, 124, 134) is adapted to store a reference to one or more gateways. The method of claim 5, wherein Each of the nodes 102, 112, 120, 130, 140 or the VLRs 108, 118, 126, 136, 142 in the nodes identify the correct HLR for all subscribers operating in the network. And a look-up table (104), adapted to update the look-up tables with changes in the HLRs. The method of claim 6, The nodes (102, 112, 120, 130) are adapted to provide location information from the HLRs (106, 116, 124, 134) to the external network. A method of managing services from a communication network to external communication networks or from external communication networks, the method comprising: The communication network comprises a plurality of nodes (102, 112, 120, 130, 140) and a plurality of subscribers forming a switching and management infrastructure (SwMI) together with other elements of the network. To Each of the nodes 102, 112, 120, 130, 140 has a visitor location register (VLR) 108, 118, 126, 136, 142, and of the nodes 102, 112, 120, 130. At least some have home location registers (HLRs) 106, 116, 124, 134, and at least some of the nodes 102, 120 with the HLRs 106, 124 are gateways 110, 128. )To have, All nodes 102, 112, 120, 130 with HLRs 106, 116, 124, 134 are assigned to nodes 102, 120 with gateways 110, 128 (204), and the SwMI is assigned to the gateway. Directing all calls to the subscribers of the network (100) and all the calls from the subscribers to the external network via the assigned node. The method of claim 8, The nodes 102, 112, 120, 130, 140 are performed as a result of a) the step of performing the assignment being a) predefined, b) controlled by an external network, or c) searching for a node with a gateway. Service node, adapted to perform the assignment to the node having a gateway (110, 128). The method of claim 9, The first node 102 with the first gateway 110 is connected to the first node 102 when the first gateway 110 is not available or the characteristics of the first gateway 110 are changed. Transmitting data from the belonging first HLR (106) to a second node (120) having a second gateway (128). The method of claim 8, And the communication network comprises an ad-hoc communication network. The method of claim 8, And the communication network comprises a private communication network.

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