In radio communication system, a radio link is a logic connection between one terminal and one access point in a radio access system, and it physically consists of one or more radio bearer transmissions. There is at most one radio link between the terminal and one access point (typically referring to a cell) in the radio access system. A radio link identification is used to identify the radio link, and each radio link related to the terminal has a unique radio link identification.
An interconnection of type B (IUB for short) interface is a logic interface between a radio network controller (RNC) and a node B. An IUB interface protocol framework consists of two function layers: a radio network layer and a transport network layer. Node B application part (NBAP) is a part in the radio network layer, and it accurately and completely specifies the functional behavior of the node B. The NBAP basic process can be divided into a public process and a dedicated process that respectively correspond to a public link signaling process and a dedicated link signaling process. The public process is applied to signaling that is already in the node B but has no relationship with the specific terminal or a specific terminal context initialization request process, including: establishing a first radio link of the terminal and selecting a service termination port. The dedicated process is a process of associating with a specific terminal context; after the RNC allocates the service termination port to the terminal through the public process, each subsequent signaling related to the terminal interacts with each other by using the dedicated process via a dedicated control port of the node, including: adding, releasing and reconfiguring a radio link for a specific terminal.
An interconnection of RNC (IUR for short) interface is an interface used by the RNC to interact signaling and data with other RNCs, and it is an interconnection bond between radio network subsystems. With the IUR interfaces, different radio network subsystems can be connected together, and mobility management of the terminal connected with the RNC crossing the radio network subsystems can be fulfilled by a dedicated protocol—radio network subsystem application part (RNSAP), including the functions such as handoff between the radio network subsystems, radio resource processing and synchronization, and so on.
When a terminal establishes a connection to a radio access network and soft handoff is happened at the IUR interface, resource of more than one RNC will be used, and different RNCs play different roles at the time:
serving RNC: the serving RNC refers to a RNC keeping the terminal connecting with an interface of a core network. The serving RNC is responsible for data transport between the core network and the terminal, and for forwarding and receiving interface signaling with the core network; for performing radio resource control and layer 2 processing to data at an air interface; and also for executing a basic radio resource management operation, such as handoff judgment, outer-loop power control and conversion from parameters of radio access bearer to transport channel parameters of the air interface.
drift RNC: the drift RNCs refer to all other RNCs except the serving RNC. The drift RNC controls the cell used by the terminal, and if desired, the drift RNC can perform macro diversity merger. Unless the terminal uses a public transport channel, the drift RNC can not perform layer 2 processing to the data at the terminal plane, while only transfers the data at the air interface transparently to the serving RNC via the routing of the IUR interface. One terminal might have more than one drift RNC.
The IUR interface has the following three main functions: management of the basic mobility between the RNCs, and service flows for supporting the public channel and for supporting the dedicated channel. These service flows are the most basic functions of the IUR interface, and RNCs from different manufactures have to fulfill compatibility of these service flows, otherwise, the interconnection of the IUR interfaces is meaningless.
The terminal context is a basic concept to which each main function of the IUR interface relates. The terminal context contains the information needed for communicating between the drift RNC/drift node B and a certain specific terminal. The terminal context is created in a radio link establishment process or an uplink signaling transport process which occurs when the terminal initially accesses to a cell controlled by the drift RNC/drift node B. The terminal context is deleted when there is no radio link or public transport channel established for the terminal due to a radio link deletion process, a public transport channel resource release process or a downlink signaling transport process related to this terminal.
A connection frame number (CFN) provides a public frame reference used by the layer 2 between a universal mobile telecommunication system terrestrial radio access network (including the node B and the RNCs) and a terminal. Essentially, the CFN is a counter of frames used to synchronize the transport channel of layer 2 between the universal mobile telecommunication system terrestrial radio access network (including the node B and the RNCs) and the terminal. For a block of transport data, the receiving end and transmitting end of the air interface have the same CFN. However, the CFN is not transmitted at the air interface. A system frame number (SFN) of each cell is transmitted on a broadcasting channel of the cell, thus with a mapping relationship between the CFNs and the SFNs, the SFN at the two ends of the air interface can be kept consistent. The value range of the CFN is from 0 to 255, with a cycle of 256 frames for recycling. In the existing radio access technology, a length of one frame is 10 ms.
In the existing systems, the purpose of a high speed uplink packet access (HSUPA) technology is to improve capacity and data throughput in an uplink direction, and reduce the delay in a dedicated channel. The HSUPA technology introduces a new transmission channel, i.e., an enhanced dedicated channel, with improving the implementation of a physical layer and a media access control layer, so as to achieve a maximum theoretical uplink data rate of 5.6 megabits per second. The HSUPA technology retains the characteristics of the soft handoff. For a terminal, there is an active set of the enhanced dedicated channel. In the active set of the enhanced dedicated channel, the cell in which the terminal receives absolute grant scheduling from the node B (which may belong to the serving radio network controller or the drift radio network controller) is called a serving enhanced dedicated channel cell, and the corresponding radio link (which is a radio link in the cell) is called a serving enhanced dedicated channel radio link identifying with the radio link identification. In the active set of the enhanced dedicated channel, a cell set, which at least includes the serving enhanced dedicated channel cell, of the same relative grant which can be accepted and merged by the terminal is called a serving enhanced dedicated channel cell set, and the corresponding radio link set (which is a set of radio links in each cell) is called a serving enhanced dedicated channel radio link set identifying with a radio link set identification. In the active set of the enhanced dedicated channel, the cell not belonging to the serving enhanced dedicated channel cell set is called non-serving enhanced dedicated channel cell, and the corresponding radio link (which is a radio link in the cell) is called non-serving enhanced dedicated channel radio link identifying with a radio link identification.
With development of the technology, a dual-carrier high speed uplink packet access technology (which allows the terminal to transmit data with the high speed uplink packet access technology over two carriers, so that the uplink data rate can be doubled) is desired to be introduced into the existing system. Moreover, the dual-carrier high speed uplink packet access technology can be used bonding with the existing dual-carrier high speed downlink packet access technology, and both of the technologies together are referred to as a dual-carrier technology. The expected scenarios of the dual-carrier technology are: a single-carrier high speed uplink packet access technology in an uplink direction and a single-carrier high speed downlink packet access technology in a downlink direction; a single-carrier high speed uplink packet access technology in an uplink direction and a dual-carrier high speed downlink packet access technology in a downlink direction; a dual-carrier high speed uplink packet access technology in an uplink direction and a dual-carrier high speed downlink packet access technology in a downlink direction. A carrier containing a high speed dedicated physical control channel in the dual-carrier technology is called an auxiliary carrier, and the other carrier remained in the dual-carrier is called a auxiliary carrier. For a terminal, each layer of the carrier in the dual-carrier has its own independent active set of the enhanced dedicated channel. At the frequency of the layer of the auxiliary carrier, in the active set of the enhanced dedicated channel of the auxiliary carrier, the Node B to which the serving enhanced dedicated channel radio link of the auxiliary carrier belongs is called a serving node B, other nodes B are called non-serving nodes B. Wherein: the serving node B might belong to a serving radio network controller or a drift radio network controller.
The serving node B controls the activation and deactivation of the enhanced dedicated channel radio link of the terminal (the enhanced dedicated channel radio link here can be the serving enhanced dedicated channel radio link managed by the serving node B or the non-serving enhanced dedicated channel radio link), and the serving radio network controller is responsible for coordinating the activation and deactivation of the non-serving enhanced dedicated channel radio link of the terminal by the non-serving node B. This control process is shown in FIG. 1, and when the serving node B belongs to the serving radio network controller and the non-serving node B belongs to the drift radio network controller, each control step is described as follows:
A: The serving node B controls the terminal to perform activation or deactivation of the enhanced dedicated channel radio link via the air interface, and the terminal confirms receiving a command of activation or deactivation of the radio link of the serving node B. The terminal executes the command of activation or deactivation of the radio link.
B: The serving node B notifies activation or deactivation information of the radio link of the terminal to the serving radio network controller via the IUB interface.
C: The serving radio network controller is responsible for coordinating activation and deactivation of the non-serving enhanced dedicated channel radio link of the terminal by the non-serving node B. The serving radio network controller sends a control command to the drift radio network controller to which the non-serving node B belongs via the IUR Interface, to command activation or deactivation of the non-serving radio link.
D: The drift radio network controller notifies the non-serving node B belonging to it to process the command of activation or deactivation of the non-serving enhanced dedicated channel radio link of the terminal.
However, the control process is not taken into account in the prior art when the serving node B belongs to the draft radio network controller rather than a serving radio network controller. As shown in FIG. 2, the serving node B belongs to the drift radio network controller, and each step in the control process is described as follows:
AA: The serving node B controls the terminal to perform activation or deactivation of the enhanced dedicated channel radio link via the air interface, and the terminal confirms receiving the command of activation or deactivation of the radio link of the serving node B. The terminal executes the command of activation or deactivation of the radio link.
BB: The serving node B notifies activation or deactivation information of the radio link of the terminal to the drift radio network controller via the IUB interface.
Due to no routing, the serving node B cannot directly report to the serving radio network controller, but can only report to the drift radio network controller via the IUB interface, as described in the above-mentioned step BB. However, the serving radio network controller can not acquire whether the above terminal performs the activation or deactivation of the enhanced dedicated channel radio link, so that the serving radio network controller cannot coordinate the activation and deactivation of the non-serving enhanced dedicated channel radio link of the terminal by the non-serving node B.
Thus, when in a scenario the serving node B does not belong to the serving radio network controller while belongs to the draft radio network controller, it results in that the non-serving enhanced dedicated channel radio link in the non-serving node B of the terminal cannot be activated or deactivated, thereby resulting in that the dual-carrier technology is not available in this scenario.