Patent Application
20060209706
Monitoring traffic for a Node B is important for deploying, testing, and monitoring a mobile network. A Radio Network Controller controlling a Node B communicates with the Node B via a UNI link to a private ATM network and then to a UNI link to the node B. When a UNI is used to connect the RNC in to the ATM network it is possible to monitor traffic for a Node B because the UNI has an identifiable channel. However, when the RNC access the ATM network directly using a PNNI link, then it is impossible to monitor traffic for the Node B at the RNC because the identity of the ATM channel used to carry traffic to the Node B (via its UNI) is unknown. There is a need to monitor traffic for a Node B at an RNC when the RNC connects with the ATM network directly using a PNNI.
Some relevant acronyms are well known in the art of wireless networks but are repeated here for the reader's convenience. The term “UMTS” refers to the Universal Mobile Telecommunications System, which is a known industry standard for a type of mobile telecommunications system. The term “CN” refers to a core network. The term “Node B” refers to a UMTS base station or physical tower. The term “RNC” refers to a radio network controller. The term “lub” refers to an interface or link between a Node B and an RNC. The term “lur” refers to an interface or link between an RNC and another RNC. The term “lu” refers to an interface or link between an RNC and a CN. The term “UTRAN” refers to a UMTS terrestrial radio access network, which is an actual implementation of a UTMTS. The term “UNI” refers to a User Network Interface. The term “PNNI” refers to a Network to Network Interface. The term “PVCC” refers to a Permanent Virtual Channel Connection. The term “HEC” refers to Header Error Control. The term “SVC” refers to Switched Virtual Circuit.
Additionally, the term “VPI” (virtual path indicator) refers to an 8-bit or 12 bit field in the header of an ATM cell. The term “VCI” (virtual channel indicator) refers to a 16-bit field in the header of an ATM cell. ATM switches use the VPI/VCI fields to identify the next VCL (virtual channel link) that a cell needs to transit on its way to its final destination. In other words, the VCI together with the VPI is used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its destination. ATM switches use the VPI/NCI fields to identify the next network VCL (virtual channel link) that an ATM cell needs to transit on its way to its final destination. The terms “user plane” and “control plane” are well known in the art and are discussed in the IEC publication mentioned below. They generally refer to user-oriented packets (user plane) and control or system oriented packets (control plane).
There is a need to monitor mobile networks. Presently, most mobile networks are Second Generation (“2G”) networks. Third Generation (“3G”) mobile networks are in development. Like 2G networks, 3G networks have cell towers called Node Bs. The RNC that controls a cell tower uses an ATM network. From the RNC data is communicated to multiple Node Bs. One RNC may control many, even several hundred, Node Bs. The RNC may be at one location, and Node Bs controlled by the RNC may be at remote sites such as at the top of a building, on top of a remote hill, etc. Often, instead of building an ATM network from scratch, he operator or mobile provider will use another entity's ATM network. This ATM network is sometimes called a private ATM network. The switches within the private ATM network use PNNI to cooperate. PNNI is a protocol is for distributing topology information between the ATM switches of the private network and is used to compute paths through the private network. At the edges of the private ATM network a customer such as a mobile provider or other user connects to the private ATM network, tells the private ATM network what is needed, etc.
An ATM identifies a channel using a VPI and a VCI. For example, the Node Bs associated with a particular RNC may each have their own public VPI and VCI. However, the private ATM network 52 will use different private VPIs and VCIs to route cells between then RNC 50 and the Node B 54. Usually, a customer or subscriber, such as a mobile telephone provider, will not have access to the internal PNNI routing information of the private ATM network 52. For instance, a user will not know the private VPIs and VCIs used for routing within the private ATM network 52.
When the RNC uses a PNNI, it in effect becomes part of the private ATM network. Within the RNC, communications are sent to the static or known VPI.VCI of the Node B. However, the traffic for the Node B is difficult to monitor at the RNC because the private ATM network will use its own internal VPI and VCI to internally route the Node B's traffic. In other words, the user at the RNC knows the VPI.VCI of the Node B, but when the equipment manufacturer allows direct access to an ATM edge switch via a PNNI link, the RNC effectively becomes part of the private ATM network and a network monitor only has access to the PNNI.
One technique is to monitor the PNNI signaling messages that go across the PNNI at a monitoring point to determine the mapping of the UNI VPI.VCI to the PNNI VPI.VCI at the monitoring point.
Although the PNNI protocol is a highly complex protocol, it is possible to facilitate monitoring of the traffic for a Node B at the PNNI of an RNC.
Embodiments discussed above relate to monitoring mobile telephone signaling carried by an ATM network to determine channels of interest. ATM cells of the ATM network are intercepted to monitor a UMTS terrestrial radio access network (UTRAN). The intercepted ATM cells are automatically analyzed to obtain a correspondence between a static Node B channel and a different private channel of the ATM network that is used to carry traffic to/from the Node B. The correspondence and other correspondences may be stored in a lookup table. A Node B's VPI.VCI, a VPI.VCI of a connected number may be extracted from a connection message. A call reference may be extracted from the connection message and stored in association with the correspondence. A connection breakdown message may be detected and, based on the release message matching the previously stored call reference, the stored correspondence that is associated with the call reference may be deleted.
The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
