JPH1070770A - Efficient carrier sensing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a message communication amount between both entities by reporting only the change amount of a result to a high-order entity by an execution entity at the time of executing carrier sensing in a base station system. SOLUTION: The high-order entity 1 reports all carrier numbers for performing carrier sensing and carrier sensing start to a low-order entity 2. The low-order entity 2 stores the carrier sensed results of all channels (the respective carriers of respective slots) in an internal memory and reports them to the high-order entity 1 at the point of time when the carrier sensing of all the channels is ended. The high-order entity 1 stores reported results as resource management data. The low-order entity 2 continues the carrier sensing thereafter as well and reports only the changed carrier sensing level (new result) of the channel to the high-order entity 1 only when change exceeding a threshold value set beforehand is generated in the result of carrier sensing. The high-order entity 1 updates the resource management data only for the new result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is, PHS (P ers
It relates to an efficient carrier sensing method in a wireless communication system, such as a onal H andy phone S ystem).

[0002]

2. Description of the Related Art In the PHS standard, an entity is defined as "a concept modeling a functional module required by a corresponding layer in order to perform communication".
That is, depending on the system, these may exist as tasks (program modules) in the same processor (CPU or the like), or the processor may be regarded as an entity and may be in the form of an upper CPU and a lower CPU. That is, the entity means “a functional block that actually performs processing”.

[0003] Normally, a lower layer executing entity for performing carrier sensing notifies a specific slot for performing carrier sensing, its carrier frequency (carrier number), and the like by a message each time from an upper layer entity for managing radio resources. The results of the carrier sense are reported in a message. This sequence is shown in FIG. FIG. 3 is a sequence diagram showing the procedure of messages between the upper entity and the lower entity. Commands are issued from the upper entity 1 for each carrier, one by one for each of the synthesizer setting, antenna setting, and carrier sense. The lower entity 2 receiving this carries out carrier sense only for the designated carrier each time and reports the result to the upper entity each time.

[0004]

According to the PHS standard, it is required to perform carrier sensing within 2 seconds before transmitting a communication carrier, so that the base station performs carrier sensing for all carriers for communication. We always go. Assume that the communication carrier is 16 carriers, the communication slot is 3 slots, and the execution synchronization of the carrier sense is 800 m.
In the case where s is set and three messages are required for the execution instruction of carrier sense from the upper entity to the lower entity, and one message is required for the result report from the lower entity to the upper entity, the communication amount between both entities is 240 messages per second. .

[0005] This communication amount imposes a heavy load on both entities, and requires high processing capability of the processor, which leads to high costs.

In addition, there is a possibility that the reliability of the system is impaired due to a communication failure between the entities.

As described above, in the PHS, the transmission conditions of the communication carrier are specified by the standard. In order to satisfy this standard, the base station needs to always carry out carrier sense of the communication carrier. In a typical base station system, the entity that performs carrier sense and the entity that manages the result of carrier sense are often different, and a huge amount of message communication is required between the two entities to instruct carrier sense and report the result. Becomes The present invention is intended to reduce the amount of message communication between both entities by the execution entity reporting only the amount of change in the result to the higher-level entity when implementing carrier sense.

[0008]

In order to solve the above-mentioned problems in the prior art, an efficient carrier sensing method according to the present invention comprises a carrier sense instruction and a carrier sense function block which are used by a radio communication device to execute carrier sense and manage the result. A procedure for notifying the lower entity of all carrier numbers and a carrier start command for performing the carrier sensing by the upper entity, comprising a higher entity for managing the result and a lower entity for performing carrier sense; and A procedure for storing all carrier numbers, executing each carrier sense, detecting and storing each level, and notifying the upper entity of the detected levels of all the stored carrier numbers. Repeat for each carrier sense Executed consisting of steps of notifying the detection result of miso-level entity for carrier number detection result changes of procedures and detection level that has been previously stored update the detected and stored each level.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing a part directly related to the present invention in a wireless communication device (PHS base station) according to an embodiment of the present invention. The upper entity (processor) 1 and the lower entity (processor) 2 execute wireless communication. It consists of part 3.

[0010] When the communication carrier starts communication with a neighboring system, the interference level increases, and when the communication ends, the interference level decreases. Therefore, the amount of change in the interference level is usually small. In the PHS standard, the carrier sense level is divided into three levels, that is, a first level (26 dBμV) or lower, a second level (40 dBμV) or lower, and a level higher than the second level. It is supposed to be good.

Therefore, as shown in the sequence diagram of FIG. 2, the upper entity 1 first notifies the lower entity 2 of all carrier numbers for performing carrier sensing and the start of carrier sensing. The lower entity 2 stores this in an internal memory, and starts carrier sense in response to a carrier sense start command. The lower entity 2 stores the carrier sense results of all channels (each carrier of each slot) in the internal memory, and reports the result to the upper entity 1 when the carrier sense of all channels is completed. The upper entity 1 stores all the reported detection levels in the memory. The lower entity 2 continues carrier sense thereafter, and reports only the changed channel carrier sense level (new result) to the upper entity 1 only when a change occurs in the carrier sense result.
The upper entity 1 updates the memory only for the new result reported.

The carrier sense result reported from the lower entity 2 to the upper entity 1 only needs to know at least three steps defined by the standard, but may be divided into finer levels according to the system. Then, the trigger of the report from the lower entity 2 does not necessarily need to be immediately notified when the result has changed. However, when a channel whose reported result is lower than the first level exceeds the first level, or when there are no channels lower than the first level, a channel lower than the second level is higher than the second level. In such a case, it is necessary to immediately report the new result to the upper entity.

[0013]

According to the comparison of the message volume between the two entities, if ten calls are made in a neighboring area in ten minutes, the conventional method is 144,000 (= 10 minutes × 60 seconds / minute × 240 times / 240 times). Second) message was transmitted and received, whereas in the present invention, 23 (= 3 times + 2 times / call × 10)
Call) message, so that the traffic can be significantly reduced.

By reducing the traffic, the load on both entities is reduced, and the following advantages are obtained.

System Cost Reduction Since the load on both entities is reduced, the number of processors can be reduced or a processor having a low processing capability can be substituted, so that the system cost can be reduced.

Improving System Reliability Since the amount of messages is reduced, the frequency of occurrence of failures such as communication errors is reduced, and furthermore, the evaluation during system development and the investigation of failures are facilitated. is there.

Broad Applicability The present invention can be applied to a wide range of applications because it can be applied to communication between processors and communication between tasks.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a part directly related to the present invention in a wireless communication device (PHS base station) according to an embodiment of the present invention.

FIG. 2 is a sequence diagram showing a procedure of a message of an upper entity and a lower entity according to the embodiment of the present invention.

FIG. 3 is a sequence diagram showing a procedure of a message of a higher-order entity and a lower-order entity in a conventional example.

[Explanation of symbols]

 1: Upper entity 2: Lower entity 3: Wireless communication execution unit

Claims (1)

[Claims] 1. A radio communication apparatus comprising a higher-order entity for managing carrier sense commands and results and a lower-level entity for executing carrier sense as a functional block for executing carrier sense and managing the result. A procedure for notifying the lower entity of all carrier numbers and a carrier start command for performing carrier sense, and the lower entity storing all notified carrier numbers, executing each carrier sense, detecting and storing each level; The procedure for notifying the upper entity of the detection levels of all the stored carrier numbers, the procedure of repeatedly executing each carrier sense for all carrier numbers stored by the lower entity, detecting each level and updating the storage, and the previous procedure. Of the stored detection levels Efficient carrier sensing method characterized by comprising the detection results of the miso for output results change carrier number and a procedure for notifying the upper entity.