KR100275516B1 - Multimedia call processing method in hierarchical cellular system - Google Patents

Abstract

1. Technical field to which the invention described in the claims belongs

The present invention relates to a call processing method for allocating a cell layer and a channel to be served according to a speed of a mobile station and a type of call in a hierarchical cellular system.

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2. Technical Problems to be Solved by the Invention

It is an object of the present invention to provide a method of processing a multimedia call in a hierarchical cellular system and a computer-readable recording medium on which a program for realizing the method is recorded.

3. The point of the solution of the invention

A method for processing a call in a hierarchical cellular system, the method comprising: a first step of assigning a channel to a data call that is not delay sensitive; A second step of blocking the call for a new voice call and a delay-sensitive new data call; And a third step of allocating channels for handoff voice calls and delay sensitive handoff data calls.

4. Important Uses of the Invention

The present invention is used for multimedia call processing in a hierarchical cellular system.

Description

Multimedia call processing method in hierarchical cellular system

The present invention relates to a call processing method for allocating a cell layer and a channel to be served according to a speed of a mobile station and a type of call in a hierarchical cellular system, and a computer-readable recording medium on which a program for realizing the call processing method is recorded.

In general, the existing call processing method considers only a voice call and considers up to a single layer or a maximum of three layers, and proposes a call processing between layers in a hierarchical cellular system.

However, the above-described conventional call processing method has a problem in that it is inappropriate for a next generation mobile communication system in which a voice call and a data call are integrated because only a voice call is considered.

According to an aspect of the present invention, there is provided a method for processing a multimedia call in a hierarchical cellular system, the method comprising the steps of: And a computer-readable recording medium storing a program for realizing the method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration example of a hierarchical cellular system to which the present invention is applied; FIG.

FIG. 2 is a diagram illustrating an example of a call processing method for each cell in each layer to which the present invention is applied. FIG.

3 is a block diagram illustrating a multimedia call processing of a base station to which the present invention is applied.

FIG. 4 is a graph showing the results of experiments on the call blocking rate and the reduction rate of the arc cutting rate when the present invention is applied.

5 is a flowchart of an embodiment of a method of processing a multimedia call according to the present invention.

According to an aspect of the present invention, there is provided a method of processing a call in a hierarchical cellular system, the method comprising: a first step of allocating a channel to a data call not sensitive to delay; A second step of blocking the call for a new voice call and a delay-sensitive new data call; And a third step of allocating a channel for the handoff voice call and the delay sensitive handoff data call.

The present invention also provides a hierarchical cellular system having a large capacity processor, comprising: a first function for assigning a channel to a data call that is not delay sensitive; A second function for blocking a call for a new voice call and a delay-sensitive new data call; And a computer-readable recording medium storing a program for realizing a third function of assigning a channel to a handoff voice call and a delay-sensitive handoff data call.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. FIG.

FIG. 1 is a diagram illustrating a configuration of a hierarchical cellular system to which the present invention is applied.

A new call processing method according to the present invention will now be described with reference to FIG.

(Handoff Voice (HV) 314, which is very sensitive to delay in handoff, such as a New Voice (NV) 312, which must be serviced in real time, New Delay Sensitive Data (NDSD) 313, and Handoff Delay Sensitive Data (HDSD) 315) allocate cells according to the speed of the mobile station, Delay Insensitive Data (DID) 311 allocates channels in the picocell 101 or the microcell 102 having a larger number of channels than in a relatively covered area.

In addition, the handoff voice call 314 and the delay-sensitive handoff data call 315 allocate a channel in a higher layer when there is no channel in the currently serving cell. In the case of a megacell (satellite cell) 104, a user subscribed to a megacell service is served.

In the apparatus for detecting the speed of the mobile station, the speed is detected first, and when the user having the threshold value X1 or less requests a channel, the service is preferentially performed in the picocell 101. [ However, a user located in an area where the picocell is not installed receives service from the microcell 102.

If the micro cell 102 is not installed, it is serviced in the macro cell 103. In the case where only the megacell 104 exists, if the user subscribes to the megacell service, the service is provided in the megacell.

In a device for detecting the speed of a mobile station, a speed is first detected. When a user having a threshold value X2 or less requests a channel, the microcell 102 allocates a channel. If the data call 311 is not sensitive to the delay and the picocell 101 is installed in the area and is serviceable, the picocell 101 services the data call 311.

Since the call is not susceptible to delay, it is not necessary to consider the handoff and it is also possible to wait until the service is received from the buffer. Therefore, the picocell 101 is more likely to receive service than the microcell 102, Is good in terms of the quality of service (QoS) of the overall system.

If the macro cell 103 is a region where the micro cell 102 is not installed and a channel is allocated in the macro cell 103 and the megacell 104 exists in the macro cell and the user subscribes to the megacell service, Service in the layer.

In the apparatus for detecting the speed of the mobile station, the velocity is detected first, and when a user having a threshold value X3 or less requests a channel, the channel is first allocated in the macro cell 103. [ If there is no channel in the macrocell, if the user subscribes to the megacell 104 service, the user is served by the megacell 104. [ If you have not joined, this issue will be closed. In the case of megacell, only some users subscribed to megacell service are served.

Regardless of the speed, the data call 311, which is not delay sensitive, services in the lowest cell that covers the area where the user is located. Accordingly, when the lowest cell in the area where the user is located is the picocell 101, the service is served by the picocell. In the case of the microcell 102, the area where the two layers are not installed is the macrocell 103 Service.

Each user is disconnected when there is no available channel in the initial access cell when requesting a new call. However, once the call initiated the call requests a handoff, if there is no available channel in the neighboring cell, the handoff is performed to the upper layer.

Through the handoff technique to the upper layer cell of the handoff cutoff call, the call cut rate due to the handoff failure can be kept very small.

In other words, hierarchical cell systems have different layers with different bandwidths in the same region. Depending on the region, there may be only one or two layers.

In the present invention, when various types of calls are input in layers and the handoff is unsuccessful, the delays are handed off to the upper layer. Even if there is no channel in the upper layer, it is possible to wait in the buffer in case of data call even though it is sensitive to delay.

2 is a diagram illustrating an example of a call processing method for each cell in each layer to which the present invention is applied.

As shown in the figure, when a user requests allocation of a channel, it can be determined that a channel is allocated or a call to wait in a buffer is determined according to the type of call and the speed of the user. Also consider a reserved channel for handoff calls. The number of reservation channels required for each layer is different.

FIG. 3 is a block diagram of a multimedia call processing of a base station to which the present invention is applied, and shows a call control method configured according to a main feature of the present invention.

As shown in the figure, it is possible to efficiently control a call when a mobile station or a user requests a channel allocation from a picocell 101 to a macrocell 103 layer.

When a user or a mobile station requests a channel allocation, a call is allocated to an appropriate layer and a cell according to a rate, and in the case of a call 311 which is not delay-sensitive, one end is stored in a buffer (322). If there is a channel that is not used by the base station, the channel is allocated (323). Otherwise, the channel is stored in the buffer (322).

The new voice call 312 or the delayed new data call 313 allocates a channel if there is a remaining channel in the base station (323), and if not, blocks (330).

The handoff voice call 314 allocates (323) the channel if there is a remaining channel in the base station, and handoffs it to the upper layer in the absence of the channel (340).

The delay sensitive handoff data call 315 allocates (323) a channel if there is a remaining channel in the base station, and waits (324) in a finite buffer if not. If there is no buffer capacity, the handoff is performed to the upper layer (340). If the waiting time has expired in the finite buffer, the handoff to the upper layer is performed (340).

In the case of the mega (satellite) cell 104, only the users subscribed to the megacell service can be served, and only the selective narrowband data service is possible, so that the megacell is not cut off and blocked.

FIG. 4 is a graph showing an experiment result of an experiment on the call blocking rate and the call reduction rate when the present invention is applied.

Figure 2 shows the probability of call truncation for a user who started using each cell based on a micro cell. The number of picocell reservation channels is 1, the buffer size is 2, the number of microcell reservation channels is 1, the buffer size is 3, The number of channels = 3, buffer size = 5, picocell (HV), handoff voice call (HV), delay sensitive new data call (NDSD), delay sensitive handoff data call (HDSD) (DID)) arrival rate = (0.2, 0.3, 0.2, 0.3, 0.2), macrocells (new voice calls, handoff voice calls, new data calls sensitive to delays, (2, 3, 2, 3, 2), the number of microcells in a macrocell = 7, the number of picocells in a microcell = 7, the number of macrocells in a megacell = 7, As the input value.

The graph shows the probability that a user of a voice and data call that initiated a call at each layer undergoes call truncation while the arrival rate of the picocell and macrocell is fixed and only the arrival rate of the microcell is changed. Since the handoff occurs at each layer, the probability of call truncation at each layer is affected by the arrival rate of the microcells.

However, using the call processing scheme of the present invention, the probability of a call-off data call (HDSD) call susceptible to delays in the picocell layer and the microcell layer is close to zero, The cutoff rate of the handoff voice call (HV) call is 10 ^-3 or less.

Therefore, the handoff call truncation rate in the microcell layer does not decrease, but the truncated call is handed off to the upper layer, the reserved channel is assigned to the handoff voice call (HV), and the handoff data call In the case of a data call (DID) that considers the queue in the HDSD and is not sensitive to the delay, the call truncation rate is remarkably reduced as shown in the figure when the call is controlled by the call processing method serviced by the lowest layer.

5 is a flowchart of an embodiment of a method of processing a multimedia call according to the present invention.

A call arrives at the base station to request a channel assignment (501). If the call is not delay sensitive (311), i.e., voice mails or paging, the call is temporarily stored in an infinite buffer (503).

After determining that there is a channel remaining in the base station after a predetermined time (504), the channel is allocated (505). If there is no channel, the channel is stored again in the infinite buffer and a timer .

If the channel is not sensitive to delay, it is determined whether there is a remaining channel in the base station (step 506). If there is an effective channel, a channel is allocated (step 505). If there is no effective channel, the validity is new voice call 312, It is determined whether the call is a data call (507).

If the call is a new voice call or a delay-sensitive new data call, the call is blocked (508); otherwise, it is determined whether the call is a handoff voice call (314) (509).

If this call is a handoff voice call, it is impossible to wait in the buffer, so handoff to the upper layer is performed (513).

If this call is not a handoff voice call, this is a delay-sensitive handoff data call 315. In this case, it is determined whether there is a remaining storage space in the finite buffer for delay-sensitive handoff data call 510 ).

If there is no remaining space, a handoff to the upper layer is performed (513), and if there is remaining space, the data is stored in a finite buffer for delay-sensitive handoff data call (511).

If there is no channel remaining in the base station (512), a channel is allocated if there is a remaining channel (505). If there is no remaining channel, If there is no handoff to the upper layer or handoff to neighboring cells or no neighboring cell or channel exists in the upper layer, the call is disconnected (513).

A channel is allocated (505), and the call is terminated and the call is handed off to the neighboring cell or the call is terminated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

In the mobile communication network in which a voice call and a data call are integrated, a handoff is performed efficiently even in a handoff between a face and a layer according to the present invention, and a better quality of service (QoS) ) Can be expected, so that an economical mobile communication network can be constituted.

In addition, there is an excellent effect of economically reducing the cutting rate of the handoff call or the call blocking rate of the new call.

Claims (9)

A method for processing a call in a hierarchical cellular system, A first step of allocating a channel to a data call not sensitive to delay; A second step of blocking the call for a new voice call and a delay-sensitive new data call; And A third step of allocating a channel for a handoff voice call and a delay-sensitive handoff data call The method comprising the steps of: The method according to claim 1, In the first step, A fourth step of allocating a channel for a data call not sensitive to the delay when a call arrives at the base station and requests channel allocation; And A fifth step of assigning a channel to a call outside the data slot not sensitive to the delay; The method comprising the steps of: 3. The method of claim 2, In the fourth step, A sixth step of determining whether the call is a data call not sensitive to the delay when a call arrives at a base station and requests channel allocation; A seventh step of storing the data call in the infinite buffer and activating the timer if the data call is not sensitive to the delay as a result of the determination in step 6; An eighth step of determining whether there is a channel remaining in the base station after a predetermined time elapses after activating the timer; A ninth step of allocating a channel if a remaining channel exists as a result of the eighth step; If the remaining channel does not exist as a result of the eighth step, repeating the seventh step; And If it is determined in step 6 that the data call is not delay-sensitive, the fifth step The method comprising the steps of: 3. The method of claim 2, In the fifth step, Determining whether there is a remaining channel in the base station; A seventh step of allocating a channel if a remaining channel exists in the base station as a result of the determination in step 6; And If it is determined in step 6 that there is no remaining channel in the base station, The method comprising the steps of: The method of claim 1, The second step comprises: A fourth step of determining whether the new voice call or the new data call is sensitive to the delay; A fifth step of blocking the call if the new voice call or the new data call sensitive to the delay is determined as a result of the fourth step; And If it is determined that the new voice call or the delayed new data call is not the result of the fourth step, The method comprising the steps of: The method of claim 1, In the third step, A fourth step of allocating a channel for the handoff voice call; And And a fifth step of allocating a channel for the delay-sensitive handoff data call The method comprising the steps of: The method of claim 6, In the fourth step, A sixth step of determining whether the call is a handoff voice call; If it is determined in step 6 that the handoff voice call is handed off to an upper layer; And If it is determined in step 6 that the handoff voice call is not received, performing the fifth step The method comprising the steps of: The method of claim 6, In the fifth step, A sixth step of determining whether there is a remaining buffer for the delay sensitive handoff data call; A seventh step of storing the remaining buffer in the finite buffer when the remaining buffer exists, and determining whether there is a remaining channel in the base station; Allocating a channel if there is a remaining channel as a result of the determination in step 7; and if the remaining channel does not exist, performing an handoff to an upper layer; And If the remaining buffer does not exist as a result of the determination in the sixth step, The method comprising the steps of: In a hierarchical cellular system with a large-capacity processor, A first function of assigning a channel to a data call not sensitive to delay; A second function for blocking a call for a new voice call and a delay-sensitive new data call; And A third function for allocating channels for handoff voice calls and delay sensitive handoff data calls Readable recording medium having recorded thereon a program for realizing the program.