Communication Device Response Collision Prevention
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Solution Overview
Problem
In wireless local area networks, particularly in the 802.11ac standard, the simultaneous transmission of downlink frames to multiple communication apparatuses can lead to collisions of acknowledgment responses, reducing communication efficiency as only one apparatus is initially permitted to respond, causing delays in completing response communication.
Innovation Solution
A communication method and apparatus that utilize code-division multiplexing for acknowledgment responses, allocating distinct response code sequences to each apparatus, allowing simultaneous transmission without collision by using a master unit to designate different transmission processes for slave units, enabling efficient radio resource allocation and response separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple communication apparatuses transmit acknowledgment responses simultaneously after receiving downlink frames, then communication efficiency is improved, but response collisions occur
Solution Approach 1:
The acknowledgment response transmission is segmented by allocating different time slots to different communication apparatuses. The master apparatus divides the response transmission opportunity into multiple non-overlapping time slots, assigning each slave apparatus a specific time slot based on its received downlink frame destination. This segmentation prevents simultaneous transmissions and eliminates collisions while maintaining high communication efficiency.
2Reliability
If only one communication apparatus is permitted to transmit the response at a time, then response collision is prevented, but communication efficiency decreases
Solution Approach 1:
The master apparatus performs preliminary action by determining the destination of each downlink frame before transmission and pre-allocating specific time slots for acknowledgment responses. By establishing the response transmission schedule in advance based on frame destinations, the system enables multiple slave apparatuses to transmit responses simultaneously in predetermined non-colliding time slots, thereby improving communication efficiency while preventing collisions.
3Productivity
If downlink frames are transmitted to multiple communication apparatuses simultaneously, then frequency utilization is improved, but response collision occurs
Solution Approach 1:
The system transitions from single-dimensional sequential response transmission to multi-dimensional parallel response transmission by introducing the time slot dimension. Different slave apparatuses transmit responses in different time slots within the same frequency band, enabling simultaneous downlink transmissions to multiple apparatuses while preventing uplink response collisions through temporal separation in another dimension.
Data Source
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AI summary
[Object] To provide a communication apparatus and a communication method, which are capable of improving the communication efficiency while preventing collision of responses in communication of responses to frames transmitted to a plurality of communication apparatuses. [Solution] Provided is a communication apparatus, including: a processing unit configured to generate a frame indicating designation information designating a transmission process for multiplexing differing for each of a plurality of other communication apparatuses; and a communication unit configured to transmit the frame generated by the processing unit to the plurality of other communication apparatuses. Also provided is a communication apparatus, including: a processing unit configured to perform a reception process of receiving a frame from another communication apparatus, and process a response to the frame in accordance with a transmission process indicated from the other communication apparatus, the transmission process differing for each of a plurality of communication apparatuses.