KR960010935B1 - Cdma - Google Patents

Abstract

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Description

Traffic Channel Management Method of CDMA Mobile Communication System

1 is a conceptual handoff.

2 is a block diagram of a CDMA base station system to which the present invention is applied.

3 is a process flow diagram in accordance with the present invention.

The present invention relates to an efficient management method of a traffic channel for transmitting voice information between a mobile station and a network at a base station in a CDMA mobile communication system.

In a mobile communication system, when a mobile subscriber moves to an area (cell) controlled by a neighboring base station during a call, a mobile station receives a stronger signal from the neighboring base station, and the mobile station reports a signal strength of the neighboring base station to the network. You will be asked.

In particular, in a CDMA cellular system using the same frequency band between cells, a handoff occurs in an area where the mobile station receives a stronger signal from the neighbor cell when moving to the neighbor cell.

Referring to FIG. 1, when a base station receives an indication of a handoff request from a network, the base station sells a non-serving traffic channel. In the conventional scheme, all traffic channels managed by the base station are assigned by the general call request. It uses the channel and the traffic channel to be allocated when requesting handoff.

However, if the base station does not manage the traffic channel that is allocated only when a handoff occurs, it is impossible to effectively provide a traffic channel when the mobile station frequently requires handoff, thus blocking the call of the mobile subscriber. This can often happen.

In general, the call blocking rate for handoff requests in mobile communication systems is lower than that for general call attempts required by mobile subscribers. This is especially true in areas with high handoff frequency, such as in metropolitan areas.

Therefore, in order to solve the problems of the prior art, the present invention, the base station has a certain number of channel resources of the total traffic channel resources as a dedicated channel for the handoff, and for the remaining traffic channel resources and handed over the general call request The purpose of the present invention is to provide a traffic channel management method of a mobile communication system that effectively manages the allocation of all off requests and effectively reduces the frequency of call disconnection for handoff requests in an environment where handoff occurs frequently.

In order to achieve the above object, the present invention provides a channel management method applied to a CDMA base station system CLA including a plurality of CDMA channel transceivers, packet routers, base station channel managers, and GPS receivers. Initializes all channel resources managed by the base station, and counts (hereinafter referred to as first count) for checking the number of traffic channels allocated to the general call and the handoff request. A first step of setting a count (hereinafter referred to as a second count) to check the number of allocated traffic channels among the j traffic channels that can be allocated only when there are no traffic channel resources for the call, and initializing these counts; When a call request message is received from a mobile station (mobile subscriber) or a network (including a public network), the received call request message is a normal call. l) a second step of checking whether it is a handoff call request or, if the received message is a request message for a general call, increase the first count by one and the number of traffic channels already allocated exceeds a certain number. If the number of assigned traffic channels does not exceed a certain number, allocating any of the available traffic channels that have not yet been allocated among the specified number of traffic channels, In this case, the service for the call request cannot be performed, and the call request is blocked, and the third step of notifying the mobile station or the network of status information, and if the received call request message is a handoff call, a general call and a handoff call A specific number of traffic channels is checked by checking whether there are any channels that have not been allocated yet and are idle. If there is an available channel that has not been allocated yet, the traffic channel is allocated to enable the service for handoff call request, and a certain number of traffic channels are allocated to manage only when handoff occurs when in service. A fourth step of checking the state of the other specific number of traffic channels, and by increasing the second count by one, a channel not yet allocated and available among other specific number of handoff-only traffic channel resources If there is any traffic channel, and if there is no more available traffic channel resource, if there is no more available traffic channel resource, handoff call request is blocked and the state information is notified to the network side. Steps.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

2 shows a schematic diagram of a CDMA base station system.

First, the CDMA channel transceiver 2a is a pilot channel used for measuring the strength of a signal received by the mobile station from the base station, a synchronization channel for transmitting information necessary for the mobile station to synchronize with the base station, and a paging channel for transmitting various information of the system to the mobile station. After converting the channel consisting of an accessor channel used by the mobile station to transmit call control information to the network and a traffic channel carrying voice information between the mobile station and the network, the baseband signal is converted into an analog signal and the transmission signal is converted into an RF signal. Conversely, the signal received from the antenna converts the RF signal of the channel into a baseband signal of the channel.

The CDMA channel manager 2b not only manages the CDMA channels processed by the channel transceiver 2a, but also transmits call control related information received from the mobile station to the network through the packet router, and vice versa. Sends various call control related information to paging channel.

In particular, when a general call or handoff request is received from a mobile station and a network, a traffic channel is allocated and a function of controlling the power of the allocated traffic channel is performed.

The GPS (Global Positioning System) receiver 2c receives time information essential for system synchronization from the satellite and transmits 10 Mhz and 1 pps (pulse per second) signals to the CDMA channel transceiver and channel manager.

The packet router unit 24 transmits not only the voice packet information of the subscriber received from the CDMA channel processing unit, but also the call control related packet information received from the CDMA channel management unit to the network side. It transmits to the management unit.

On the other hand, the algorithm for performing this function is as follows (algorithm: 3-1).

The base station channel manager (2b) checks whether a request for a general call or a handoff call occurs when an event for a call request occurs, and in the case of a general call, the number of currently allocated traffic channels exceeds the i-th channel. If it is not more than i, allocate one of i traffic channels (1 ~ i) for the general call to service the new call, and if it exceeds the i number, block the state of the general call ( New call blocking).

If the event for a call request is a request for a handoff call, first check the number of assigned traffic channel counters to check that the idle traffic of the i traffic channels (1 to i) for the general call and the handoff is not assigned yet. If there is a traffic channel, an appropriate channel of this channel block is allocated for a handoff call request. If there is no idle channel among the channels in this block, one of the (i + 1 to j) traffic channel blocks is selected. Assign for handoff call request.

However, if there are no traffic channels to be allocated even in the j handoff-only traffic channel blocks (i + 1 to i + j), a handoff call blocking state is provided to provide a service for the handoff call. It becomes impossible.

The flowchart for the algorithm (3-1) is as follows (Figure 3).

First, the base station channel manager 2b performs initialization for all channel resources managed by the base station (3a). The traffic allocated among the j traffic channels that can be allocated only when there is no traffic channel resource for the general call when the handoff is requested, and a count (Tc_count) for checking the number of traffic channels allocated when the general call and the handoff request are made. To check the number of channels, set the counts (Ho_count) respectively and initialize these counts. Here, in the former case, any unallocated traffic channels among the i traffic channels are set to ka and kb variables, and for the latter case, i.e., any available unallocated traffic channels among the j traffic channels are set to ho, respectively. (3b). The base station channel manager (2b) receives a call request message from the mobile station (mobile subscriber) or the network (including the public network) side (3c). The base station channel manager receiving the call request message checks whether the received call request message is a normal call or a handoff call request (30).

If the received message is a request message for a general call, the base station channel manager increases Tc_count by one (3e) and checks whether the number of already allocated traffic channels exceeds i (31). If the number of allocated traffic channels does not exceed i, then any channel 'ka' of the available traffic channels that has not yet been allocated among the i traffic channels is allocated (3g), and if all i traffic channels are allocated If the Tc_count exceeds i, the service for the call request cannot be provided (3h). The base station channel manager notifies the mobile station or the network side of such status information (3i).

On the other hand, when the call request message received by the base station channel manager is a handoff call, it is processed according to the following procedure.

First, it is checked whether there are any channels which have not been allocated yet in the idle channel among the i traffic channel resources for the general call light handoff call (3j, 3k). If there is an available channel that has not yet been allocated among the half-day i traffic channels, the traffic channel 'kb' is allocated to service the handoff call request (31). Otherwise, all i traffic channels are allocated and serviced. In the middle of the process, the state of j traffic channels managed to be allocated only when a handoff occurs is checked. (Ho_count is added and compared with j). (3m, 3n)

The base station channel manager checks Ho_count and allocates a random logical channel 'ho' among the j handoff-only traffic channel resources if there is an available channel (3o). However, as a result of the inspection, when all j traffic channels are allocated and there are no more available traffic channel resources, the handoff call request is blocked (3p). The channel management department of the ringback support station notifies the network side of such status information.

Claims (1)

A plurality of CDMA channel transceivers 2a. In a channel management method applied to a CDMA base station system having a packet router section 26, a base station ruler 1 management section 2b, and a GPS receiver, the base station channel management section 2b controls all channel resources managed by the base station. Perform a initialization operation for a general call and a handoff request, a count (hereinafter referred to as a first count) for checking the number of traffic channels allocated for a general call and a handoff request, and a traffic channel resource for a general call for a handoff request A first step of setting counts (hereinafter referred to as second counts) and initializing these counts in order to check the number of allocated traffic channels among the j traffic channels that can be assigned only to a mobile station (mobile subscriber) or less network ( The second step of checking whether the received call request message is a normal call or a handoff call request when receiving a call request message If the received message is a request message for a general call, the first count is increased by one, and the number of traffic channels already allocated exceeds the specified number. If the number of allocated traffic channels does not exceed the specified number, Allocates any channel among the available traffic channels that have not yet been allocated among the specified number of traffic channels, and if all the specified number of traffic channels are allocated, the service for the call request cannot be serviced and the call request is blocked. The third step of notifying the mobile station or the network side of the status information, and when the received call request message is a handoff call, a channel which is not yet allocated and is idle in the traffic channel resource specific number for the general call and the handoff call If there is an available channel that has not yet been allocated among a certain number of traffic channels, It assigns traffic channels to enable service for handoff call request, and checks the status of other specific number of traffic channels managed to allocate only when handoff occurs when all traffic of specific number of channels are allocated and in service. In step 4, the second count is increased by one, and when there is a channel that is not yet allocated among the specific number of handoff-only traffic channel resources compared to the specific number, an arbitrary traffic channel is allocated in duplicate. And a fifth step of, when all other specific number of traffic channels are allocated and there are no more available traffic channel resources, handoff call request blocking state and notifying the network side of the status information. How to manage traffic channels in your system.