CN1369161A - System and method of providing required quality of service (QOS) level for mobile-originated call routed through packet-switched network - Google Patents

Abstract

A system and method of providing a required quality of sercice (QOS) level for a call that is originated in a mobile radio telecommunications network and is routed through a Voice-Over-Internet-Protocol (VOIP) network(3). Signaling connections are established between a mobile switching center (MSC) (4) in the mobile network and at least one VOIP gateway (6). The MSC sends an Initial Address Message (IAM) (11) to the VOIP gateway and includes a new QOS Required parameter (12). The gateway confers with a gate keeper (8) in the VOIP network to determine whether the required QOS can be provided. If the required QOS can be provided, an indication that the required QOS can be provided is sent from the packet-switched network to the mobile network. If the required QOS cannot be provided, an indication (16) that the required QOS cannot be provided is sent from the packet-switched network to the mobile network.

Description

System and method for providing a desired quality of service (QOS) level for a mobile-originated call routed through a packet-switched network

Background of the invention

invention technical field

The present invention relates to telecommunications systems and, in particular, to a system and method for providing a desired level of quality of service (QOS) for mobile originated calls routed through a packet switched network.

Related technical description

There are existing and proposed network architectures for routing mobile station (MS)-originated calls (i.e., MS-originated calls) in wireless telecommunications networks through packet-switching networks such as Voice over Internet Protocol (VOIP) net. In these architectures, call establishment uses Integrated Services User Part (ISUP) signaling between a Mobile Switching Center (MSC) in the mobile network and a VOIP gateway that provides an interface to the VOIP network. However, the current ISUP interaction between the MSC and the gateway does not have any negotiation of the quality of service (QOS) level required by the mobile network. Since there is no negotiation at present, the mobile network must adopt any QOS that VOIP can provide.

Nowadays, mobile networks usually have a lower QOS than wired networks due to limitations in the air interface. For long-distance calls, mobile calls are transferred to the Public Switched Telephone Network (PSTN), which is itself a circuit-switched network, to maintain QOS. If the mobile call is routed through the VOIP network, some kind of QOS guarantee is required to ensure that the QOS does not drop below an acceptable level. The current interaction between MSC and VOIP gateway does not ensure QOS for calls.

There is no known prior art teaching as to a solution to the above-mentioned deficiencies and deficiencies disclosed herein. In order to overcome the disadvantages of existing solutions, it would be advantageous to have a system and method for providing a desired level of quality of service (QOS) for mobile originated calls routed through a packet switched network. Moreover, such a system should provide a more robust network architecture. The present invention provides such a system and method.

Summary of the invention

In one aspect, the present invention is a system for providing a desired level of quality of service (QOS) for calls originating in a mobile wireless telecommunications network and routed through a packet switched network. The system includes a mobile switching center for sending the required QOS indication from the mobile network to the packet switching network, a device in the packet switching network for determining whether the required QOS can be provided, and a device in the packet switching network for sending The gateway that the mobile network sends an indication of whether it can provide the required QOS.

In another aspect, the present invention is a method of providing a desired quality of service (QOS) level for a call originating in a mobile wireless telecommunications network and routing through a packet switched network. The method comprises the steps of: sending an indication of the required QOS from the mobile network to the packet switching network, determining whether the required QOS can be provided in the packet switching network, and then sending the instruction from the packet switching network to the mobile network once it is determined that the required QOS can be provided. An indication of the required QOS can be provided. The method may also include sending an indication from the packet switched network to the mobile network that the required QOS cannot be provided upon determination that the required QOS cannot be provided. Such an indication may also provide available QOS levels.

In yet another aspect, the present invention is a method for providing a desired quality of service (QoS) for calls originating in a mobile wireless telecommunications network and routed through a packet switching network when a mobile switching center (MSC) is connected to a plurality of packet switching networks. QOS) level method. The MSC can simultaneously send the required QOS indication from the mobile network to each of the multiple packet switching networks. Then, each packet switching network determines whether it can provide the required QOS and sends an indication of whether it can provide the required QOS to the MSC. Optionally, the MSC may sequentially query the packet switching network to determine that the QOS is available. Thereafter, it is determined in the MSC whether any packet-switched network can provide the required QOS, and then once it is determined that at least one of the packet-switched networks can provide the required QOS, the MSC selects one of the plurality of packet-switched networks to route the call.

In yet another aspect, the invention is a method of accessing a packet switched network from a mobile radio telecommunications network having an MSC. The method comprises the steps of establishing a plurality of signaling connections between the MSC and a plurality of packet switched networks, sending a plurality of access messages from the MSC to the plurality of packet switched networks. Afterwards, each of the multiple packet switching networks sends an access response message to the MSC, and then selects one of the corresponding packet switching networks to access.

Brief description of the drawings

For those skilled in the art, it will be easier to understand the present invention, and its multiple purposes and advantages will be more apparent with reference to the following drawings in conjunction with the detailed description, wherein:

Figure 1 is a simplified block diagram of a network architecture in which the method of the present invention can be implemented to provide the required QOS levels to MS-originated calls routed through a Voice over Internet Protocol (VOIP) network;

Figure 2 is a sequence diagram illustrating the message flow for routing an MS-originated call through the VOIP network between the MSC and the VOIP gateway in Figure 1;

Figure 3 is a simplified block diagram of a preferred embodiment of an architecture for routing an MS-originated call over a VOIP network and providing the required QOS level for the call;

Figure 4 is a sequence diagram illustrating the message flow of a MS originating a call through a VOIP network when the MSC is connected to more than one VOIP gateway; and

Figure 5 is a sequence diagram illustrating the message flow for routing an MS originated call when no VOIP network is able to provide the required QOS.

Implementation details

The present invention is a system and method for providing a desired quality of service (QOS) level for calls routed through packet switched networks such as Voice over Internet Protocol (VOIP) networks, Asynchronous Transfer Mode (ATM) networks, and the like. The invention is mainly applicable to calls initiated by a mobile station (MS) in a wireless telecommunication network (ie MS originated call). Furthermore, the present invention provides a more robust network architecture than currently proposed architectures.

Figure 1 is a simplified block diagram of a network architecture 1 in which the method of the present invention may be implemented to provide a desired level of QOS to a mobile station (MS) 2 originating call routed through a VOIP network 3 . The MSC 4 uses Integrated Services User Part (ISUP) messages to establish a connection 5 with a VOIP Gateway (GW) 6. The destination in the VOIP network is a terminating gateway (T-GW) 7 . Gatekeeper (GK) 8 maintains the overall status of the VOIP network with respect to latency, congestion, etc. Calls successfully routed through the VOIP network are sent from the T-GW to the Service Switching Point (SSP) 9 for further routing.

Figure 2 is a sequence diagram illustrating the message flow for routing an MS-originated call through the VOIP network 3 between the MSC 4 and the VOIP gateway 6 in Figure 1. An ISUP Initial Address Message (IAM) 11 with newly defined required QOS parameters 12 is sent from the MSC to the gateway. The required QOS parameters specify performance levels affecting QOS such as the number of router hops allowed in the VOIP network 3, the required bandwidth, and/or the allowed latency for packet transmission to the T-GW 7. The Gateway may consult the Gatekeeper 8 using the procedures outlined in H.323 to determine whether it is possible to provide the required QOS. This determination is based on the MDN provided in the IAM message, which identifies the T-GW at the destination end of the network. The gateway sends an admission request (ARQ) message 13 to the gatekeeper, and the gatekeeper determines its QOS and returns an admission confirmation (ACF) message 14 to the gateway.

Table 1 below illustrates the usage of the required QOS parameters in the ISUP Initial Address Message (IAM). ISUP Initial Address Message (IAM) The required QOS parameters are sent as optional parameters in the following format: Required QOS value Remark Optional parameter code set to any suitable value optional argument length indicator Indicates the total number of octets required for latency (latency) requests in milliseconds, router hop count requests, and available bandwidth requests Optional parameter octets Latency (latency) requests in milliseconds, router hop count requests, and available bandwidth requests

Table 1

After determining the QOS, the gateway 6 sends an ISUP address receipt message (ACM) 15 to the MSC 4, and includes an available QOS parameter 16 to indicate the QOS level that the VOIP network can provide, thereby indicating whether the VOIP network can meet the required quality of service (required QOS). If the required QOS can be supported, the call is routed to the gateway, via the VOIP network, to the SSP 9.

Table 2 below illustrates the usage of the QOS parameters available in the ISUP Address Complete Message (ACM). ISUP address receiving full message (ACM) Available QOS parameters are sent as optional parameters in the following format: Available QOS value Remark Optional parameter code set to any suitable value optional argument length indicator Indicates the latency (latency) in milliseconds, the number of router hops, and the total number of octets required for available bandwidth Optional parameter octets Latency (latency), router hops, and available bandwidth in milliseconds

Table 2

Certain applications require more bandwidth in the VOIP network than others, and multiple applications may compete for available bandwidth at any one time. A mobile call must have enough bandwidth allocated to it to ensure that the required QOS is provided. If the mobile call also has data or graphics associated with it, the VOIP network may indicate that there is only enough bandwidth available for voice. The MSC may then attempt to route the call via another VOIP network or PSTN, or may provide an announcement to the calling user that only resources are available for voice calls.

FIG. 3 is a simplified block diagram of a preferred embodiment of an architecture 20 for routing an MS-originated call through a VOIP network and providing the required level of QOS for the call. In a preferred embodiment, MSC 4 uses multiple ISUP connections 21 to communicate with multiple VOIP gateways 22-25. Each VOIP network may have multiple gateways, and the architecture may involve multiple VOIP networks. In actual implementation, this configuration may occur when the local telco runs the MSC and the competing long-distance telco runs the VOIP network.

In the example shown in Fig. 3, gateway-1A (22) and gateway-1B (23) are connected to VOIP network-1 (26), and gateway-2A (24) and gateway-2B (25) are connected to VOIP network- 2 (27). On the terminating side of the VOIP network-1 is a terminating gateway-1 (T-GW-1) 28 . Gatekeeper-1 (GK-1) 29 is also a part of VOIP Network-1. On the terminating side of the VOIP network-2 is a terminating gateway-2 (T-GW-2) 31 . Gatekeeper-2 (GK-2) 32 is also part of VOIP Net-2. Calls transmitted by VOIP net-1 or VOIP net-2 are routed to SSP 9.

A more robust architecture can be provided by connecting the MSC 4 to multiple gateways 22-25. The architecture currently envisaged uses only a single gateway, and a single gateway may fail to cause the wireless network to fail to access the VOIP network. Multiple gateways provide redundancy and provide access to the VOIP network even if a gateway fails.

Figure 4 is a sequence diagram illustrating the message flow for routing an MS originated call through a VOIP network when the MSC 4 is connected to more than one VOIP gateway and one or more VOIP networks. For purposes of explanation, the MSC is shown connected to Gateway-1A (22), Gateway-2A (24) and a number of other gateways including Gateway-N (33). In this configuration, the MSC can send ISUP messages to multiple gateways in one or more VOIP networks. Therefore, the call is more likely to be successfully established with the required QOS.

The MSC 4 sends a plurality of IAM messages 34-36, one for each connected gateway. The IAM messages each include the required QOS parameters 12 and can be sent to each gateway simultaneously or sequentially as long as the call setup time does not expire. If the IAM messages are sent sequentially, the MSC may have a preferred gateway that is always tried first.

As shown in Figure 2 above, each gateway can consult the gatekeeper associated with the VOIP network, and the gateway is connected to this gatekeeper to determine the QOS level it can provide. After determining the QOS, each gateway returns an ACM message including available QOS parameters 16 to the MSC 4 respectively. Available QOS parameters indicate the QOS level that the VOIP network can provide, thereby indicating whether the VOIP network can meet the required service quality (required QOS).

The call can then be routed in one of several alternative ways. First, the MSC can route the call to the first gateway that sends an ACM message with an available QOS that meets or exceeds the required QOS. Second, the MSC can collect responses within a predetermined time period, and then route the call to the gateway that reported the best available QOS.

Figure 5 is a sequence diagram illustrating the message flow for routing an MS originated call when none of the VOIP networks are able to provide the required QOS. The initial process is the same as described in Figure 4. MSC 4 sends a plurality of IAM messages 41-43, one for each connected gateway, wherein each message includes required QOS parameters. Then, each VOIP network determines whether it can provide the required QOS. Next, each gateway returns an ACM message to MSC 4, including available QOS parameters. In the example shown in Figure 5, none of the associated VOIP networks can provide the required QOS. Accordingly, the MSC may route the call at 48 to a node in an alternative network such as the Public Switched Telephone Network (PSTN) instead of the VOIP network. Since one of the advantages of routing calls through a VOIP network is lower charges for long distance calls, the user will pay a higher price because the call is routed through the PSTN. A suitable price can be determined, and because the user tries to make a call through the VOIP network, the operator provides the call at this VOIP network price, but the VOIP network cannot provide this service.

It is therefore believed that the operation and construction of the present invention are apparent from the foregoing description. While the systems and methods shown and described have been characterized as being preferred, it will be apparent that various changes and modifications are possible without departing from the scope of the present invention as set forth in the following claims.

Claims (20)

1. A method of providing a desired quality of service (QOS) level for a call originating in a mobile wireless telecommunications network and routing through a packet switched network, said method comprising the steps of: Send an indication of the required QOS from the mobile network to the packet switched network; determining whether the required QOS can be provided in the packet-switched network; and Once it is determined that the required QOS can be provided, an indication that the required QOS can be provided is sent from the packet switching network to the mobile network. 2. The method for providing the required QOS level in claim 1 further comprising sending an indication that the required QOS cannot be provided from the packet switching network to the mobile network once it is determined that the required QOS cannot be provided. 3. The method of providing a required QOS level in claim 2, wherein the step of sending an indication that the required QOS cannot be provided comprises sending an indication of a QOS level that can be provided. 4. The method of providing required QOS levels in claim 2, wherein the packet switched network is a Voice over Internet Protocol (VOIP) network, and the step of sending the required QOS indication from the mobile network to the packet switched network comprises A mobile switching center sends a message to a gateway in the VOIP network. 5. The method of providing required QOS levels in claim 4, wherein the step of sending a message from a mobile switching center in the mobile network to a gateway in the VOIP network includes sending an Initial Address Message (IAM) with the required QOS parameters. 6. The method for providing the required QOS level in claim 5, wherein the step of sending the IAM message with the required QOS parameters includes sending the required QOS parameters, including required waiting time, router hops and bandwidth in the VOIP network limits. 7. The method for providing the required QOS level in claim 6, wherein determining whether the required QOS can be provided in the packet switching network comprises determining whether the required pairing can be satisfied in the VOIP network from a certain gatekeeper in the VOIP network Latency, router hops, and bandwidth limitations. 8. The method of providing the required QOS level of claim 2 further comprising routing the call through an alternate network after sending an indication to the mobile network that the required QOS cannot be provided. 9. A system for providing a desired level of quality of service (QOS) for a call originating in a mobile wireless telecommunications network and routed through a packet switched network, said system comprising: A mobile switching center that sends the required QOS indication from the mobile network to the packet switched network; means for determining whether the required QOS can be provided within the packet-switched network; and A gateway that sends an indication of whether the required QOS can be provided to the mobile network in the packet-switched network. 10. The system providing the required QOS level in claim 9, wherein the packet switching network is a voice over Internet protocol (VOIP) network, and the device for determining whether the required QOS can be provided comprises a determination of waiting time in the VOIP network, router hopping number of gatekeepers and available bandwidth. 11. A method of providing a desired level of quality of service (QOS) for a call originating in a mobile wireless telecommunications network and routing through a packet switched network, said method comprising the steps of: Connect a mobile switching center in the mobile network to multiple packet switching networks; sending simultaneously an indication of the required QOS from the mobile network to each of the plurality of packet-switched networks; Determine whether the required QOS can be provided in each packet switching network; sending an indication of whether the required QOS can be provided to the mobile network from each network in the plurality of packet switching networks; determining in the mobile switching center whether there is a packet switching network capable of providing the required QOS; and Once it is determined that at least one of the packet switching networks is capable of providing the required QOS, the mobile switching center selects one of the plurality of packet switching networks to route the call. 12. The method of providing a required QOS level of claim 11, wherein the step of selecting one of a plurality of packet switched networks to route the call includes selecting the first packet switched network to send an indication that can provide the required QOS. 13. The method of providing a desired QOS level in claim 11, wherein the step of selecting one of a plurality of packet switched networks to route the call comprises the steps of: determining a time period for receiving an indication from each of the plurality of packet-switched networks that the required QOS can be provided; and The packet switched network having the highest QOS level received within the determined time period is selected. 14. The method of providing the required QOS level of claim 11 further comprising routing the call through an alternate network upon determining that no packet switched network is capable of providing the required QOS. 15. A method of providing a desired level of quality of service (QOS) for a call originating in a mobile wireless telecommunications network and routing through a packet switched network, said method comprising the steps of: (A) connecting a certain mobile switching center in the mobile network to multiple packet switching networks; (B) sending an indication of the required QOS from the mobile network to a selected packet switched network; (C) determining whether the required QOS can be provided in the selected packet switching network; (D) Send an indication of whether the required QOS can be provided from the selected packet switching network to the mobile network; (E) Determine whether the selected packet switching network can provide the required QOS in the mobile switching center; (F) once it is determined that the selected packet switching network cannot provide the required QOS, then select another packet switching network and repeat steps (A) to (E); and (G) Routing the call to the selected packet switched network once it is determined that the selected packet switched network can provide the required QOS. 16. A method of accessing a packet switching network from a mobile wireless telecommunications network with a Mobile Switching Center (MSC), said method comprising the steps of: Establishing multiple signaling connections between the MSC and multiple packet switched networks; sending multiple access messages from the MSC to multiple packet switched networks; sending an access response message from each of the plurality of packet-switched networks to the MSC; and Select one of the corresponding packet-switched networks to access. 17. The method of accessing a packet-switched network from a mobile wireless telecommunications network in claim 16, wherein the step of sending a plurality of access messages from the MSC to a plurality of packet-switched networks includes sending an indication containing a desired quality of service (QOS) level news. 18. The method for accessing a packet switching network from a mobile wireless telecommunications network in claim 17, wherein the step of sending an access response message to the MSC from each of the plurality of packet switching networks comprises sending a message containing information that can be accessed by each packet switching network. The Access Response message indicated by the QOS level provided. 19. The method of accessing a packet-switched network from a mobile wireless telecommunications network in claim 18, wherein the step of selecting one of the corresponding packet-switched networks to access comprises selecting the first one capable of providing an indication of the required QOS level to Responsive packet-switched network. 20. The method of accessing a packet-switched network from a mobile wireless telecommunications network in claim 18, wherein the step of selecting one of the corresponding packet-switched networks to access comprises the steps of: determining a time period for receiving an indication from each of the plurality of packet-switched networks that the required QOS can be provided; and The packet switched network having the highest QOS level received within the determined time period is selected.

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