KR20070026532A - Communication network and method - Google Patents

Abstract

A wireless, ad-hoc or private communications network (100) comprising nodes (102, 112, 120, 130, 140), forming with other elements of the network a switching and management infrastructure /SwMI/, and subscribers, wherein each of said nodes (102, 112, 120, 130, 140) has a Visitor Location Register /VLR/ (108, 118, 126, 136, 142), and at least a part of said nodes (102, 112, 120, 130) are provided with Home Location Registers /HLRs/ (106, 116, 124, 134) and at least a part of said nodes (102, 120) with said HLRs (106, 124) are provided with gateways (110, 128), wherein in said network (100) every node (102, 112, 120, 130) with an HLR (106, 116, 124, 134) is assigned to a node (102, 120) having a gateway (110, 128) and said SwMI directs calls to and from a subscriber of said network (100) to an external network via said assigned node with a gateway. ® KIPO & WIPO 2007

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 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 connecting to 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 performs the functions necessary to manage in a conventional cellular communication network, 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 vary from time to time, such that at any one time a node can provide the services and at other times the services can 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 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 call services, especially group services in a true ad hoc network at high speed. 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 be available or have external connections available depending on the state of the network. If the mobile users or they are fully 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, which routes calls originated by the mobile user. It makes it difficult to decide how to do it.

Accordingly, there is a need for a method of controlling and identifying the location information of subscribers in a communication network and the nodes on which gateways are deployed when the network is required to operate independently of reconfiguration processes so that the aforementioned disadvantages can be mitigated or overcome. do.

Accordingly, the present invention preferably alleviates or eliminates the aforementioned disadvantages either 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, a method is provided for mitigating services to or from external communication networks in an ad-hoc or private communication network as claimed in claim 16.

The invention advantageously,

Explicitly access services outside a deployable or ad-hoc mobile network via gateways,

Determine gateways suitable for performing communication 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 assigns 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 simplifies 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, ie identifying the correct HLR for each block of identifiers. . 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 detailed description focuses on embodiments of the 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, PACO Project 25 or GSM and other digital and analog communication systems).

Referring to FIG. 1, a wireless, ad-hoc or private communications network 100 (after being referred to as a network) in accordance with one embodiment of the present invention is shown. 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, Has 128. All nodes with an HLR are assigned to nodes with a gateway, and as a result of the assignment, the SwMI sends all calls directly to and from the subscriber through the assigned gateway. If the first subscriber stored at 116 requests a call to the external network, SwMI sends the call directly through the first gateway 110 when the third node 112 is assigned to the first node 102. .

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 and the look-up table 104 to identify nodes whose data belonging to a particular subscriber are included in the HLR. Has a subset of the data. If the call is sent 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 the information indicated by the node where the subscriber is currently located.

According to another embodiment of the present invention, nodes provided with gateways and not connected to an external network can be identified. In this case, subscribers are not assigned to HLRs at these nodes, but gateways are assigned to HLRs at nodes to which external networks are connected.

According to another embodiment of the invention, the subscriber's data may be included in the HLRs 106, 116, 124, 134 deployed in some 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 first HLR 106 and the first gateway 110, the reference of the HLR is related to the gateway located at the same node, for example the first HLR 106 is the first gateway. There is a reference to 110, but this does not have to be as described above.

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 (in a situation when the gateway 110 is not connected or operable to an external network), the gateway ( The previous criteria of the HLR 116 indicating 110 is rearranged to indicate the gateway 128.

The external network has information indicating the appropriate gateway for each subscriber or group. In this manner, if 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, and once the call is received by the gateway, the gateway can display individual subscriber or group data. The location information may be recovered to route each call by searching each of the reference HLRs to find the actual HLR including. Routing of calls within the network can be done directly by the gateway when receiving routing information from the HLR or by sending the call to the node where the subscriber or group's HLR is deployed, which node can be connected to the subscriber or group. Send the call.

It can be seen that this embodiment relates to the case where all gateways do not have a connection to an external network. HLRs contain criteria for gateways that do not have connections to the external network and the gateways have corresponding criteria for all HLRs.

It can be seen that the criteria between HLRs and gateways can be unusual in that only one HLR refers to one gateway and only gateway refers to any one HLR. However, in other embodiments, the criteria are not peculiar, and calls from the external network are directed to subscribers or groups when each gateway 110, 128 is located at a node where a copy of the look-up table 104 is located. Because the correct HLR for the network 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 application configuration.

In another embodiment of the invention, the assignment from one node to a node having a gateway is controlled by an external network. In this embodiment, the configuration of the table 104 is by an external network, which may determine which gateways are best suited for routing calls destined for 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 nodes with gateways. 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 120, respectively. Once the node with the gateway is found by the discovery process, the HLR can record the criteria for the 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 the appropriate first gateway 110, and storing the criteria at the first node 102 and May provide a reference to itself (ie, the third HLR 116) to the first gateway 110.

The discovery process involves external networks 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 parameters. Gateways with any connection characteristic to the network, or any combination thereof, may include known techniques for providing criteria for the gateways with desirable features.

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 operating on nodes 102, 112, 120, 130, 140.

As a result of a search for the network or a manually initiated update, subscriber information contained in one HLR may be moved to another HLR. For example, if the first gateway 110 disposed in the first node 102 is separated or removed from the external network, the subscriber's information contained in the first HLR 106 is connected to the connected second gateway 128. It may be transmitted to the second HLR 124 disposed in the second node 120 having a. The look-up table 104, which describes the assignment of subscribers to HLRs, will 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 detached or removed from the first gateway 110 deployed at the first node 102, for example. May refer to a second node 120 having a 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 node including the second gateway 128. May be moved to a second HLR 124 disposed at 120. The network 100 is updated with a new location of data previously stored in the first HLR 106 in order to fully operate all the VLRs 108, 118, 126, 136, 142 in the network 100. Alternatively, they indicate 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 the information from which records from the first HLR 106 are sent.

Optionally, the subscriber's data may be placed in another HLR, such as a third HLR 116 of the third node 112 where the gateway is not located, and the third HLR 116 may be configured by a subscriber from an external network. Criteria may be given for the second gateway 128 disposed in the second node 120 to access through the gateway 128.

In one embodiment, the configuration of the subscribers in the HLRs 106, 116, 124, 134 or the assignment of the subscribers to these HLRs 106, 116, 124, 134 may comprise 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 need services that require a gateway, the subscriber's HLR entry may be made at any suitable node in the network. Typically, this can be done at a node close to the normal location of the 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 the first node 102 with the gateway and the first node is reconfigurable (206), the HLRs 204 assigned to the first node. Is sent to another node with 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, records of the HLR sent to the first node 102 are assigned to the first node 102 as a separate HLR in addition to the first HLR 106 that is assigned to the first node 102 prior to transmission. This solution is particularly advantageous when the node is temporarily disconnected from the network 100 (which facilitates retransmission).

Optionally, instead of transmitting, the HLR criteria in each HLR are updated to indicate the node with the gateway.

Claims (10)

As a wireless, ad-hoc or private communications network 100, The network 100 includes a plurality of nodes 102, 112, 120, 130, 140 and a plurality of subscribers forming a switching and management infrastructure (SwMI) along with other elements of the network. , ad-hoc or private communication 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, In the network 100, all nodes 102, 112, 120, 130 with HLRs 106, 116, 124, 134 are assigned to nodes 102, 120 with gateways 110, 128. SwMI is adapted to direct all calls to subscribers of the network 100 and all calls from subscribers to an external network via the assigned node with a gateway, wireless, ad-hoc or private communication network 100. The method of claim 1, The nodes are configured to perform the assignment to the node with a gateway if the assignment is performed as a result of a) being predefined, b) controlled by an external network, or c) searching for a node with a gateway. A wireless, ad-hoc or private communication network 100 adapted. The method according to claim 1 or 2, The first node 102 with the first gateway 110 may be configured to: a) the first gateway 110 is not available or b) the characteristics of the first gateway 110 are changed. A wireless, ad-hoc or private communication network (100) adapted to transmit data from a first HLR (106) belonging to a node (102) to the second node (120) with a second gateway (128). The method according to claim 1 or 2, The first node 102 with the first gateway 110 may be configured to: a) the first gateway 110 is unavailable or b) the features of the first gateway 110 are changed. A wireless, ad-hoc or private communication network (100) adapted to generate a reference from a first HLR (106) belonging to a first node (102) to a second node (120) having a second gateway (128). The method of claim 4, wherein One or more of the HLRs (106, 116, 124, 134) are adapted to store a reference in one or more gateways. The method according to claim 4 or 5, 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 according to any one of claims 1 to 6, The nodes 102, 112, 120, 130 are adapted to provide location information from the HLRs 106, 116, 124, 134 to the external network, wireless, ad-hoc or private communication network 100. . A method for managing services from or to external communication networks in an ad-hoc or private communication network, the method comprising: Wherein the ad-hoc or private communication network comprises a plurality of nodes and a plurality of subscribers forming a switching and management infrastructure (SwMI) together with other elements of the network. Each of the nodes has a visitor location register (VLR), at least some of the nodes have home location registers (HLRs), at least some of the nodes with the HLRs have gateways, In the service management method, all nodes with the HLR are assigned to the node with the gateway (204), and the SwMI sends all calls to subscribers of the network (100) via the assigned node with the gateway. And direct all calls from the subscriber to an external network. The method of claim 9, The nodes may assign the assignment to the node with a gateway if the step of performing the assignment is performed as a result of a) being predefined, b) controlled by an external network, or c) searching for a node with a gateway. A service management method, adapted to perform. The method according to claim 8 or 9, The first node with the first gateway is the second node with a second gateway from a first HLR belonging to the first node if the first gateway is not available or the characteristics of the first gateway are changed. A service management method for transmitting data to a node.

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