Hierarchical TIM Encoding for Low-Power Terminal Energy Savings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless local area networks, terminals face high power consumption due to the need to decode all traffic indication map (TIM) blocks, even when there is no data, especially in environments with intermittent small data transmissions, such as sensor networks.
Innovation Solution
A method is introduced where a terminal extracts a page index and block bitmap information from an encoded TIM to determine if decoding is necessary, allowing it to skip decoding unnecessary blocks and enter a power save mode when no data is indicated, thereby reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all TIM blocks are decoded to determine data presence, then complete information about data transmission status is obtained, but power consumption increases significantly
Solution Approach 1:
The patent extracts only the necessary information (block bitmap and page index) from the TIM structure to determine data presence, rather than decoding the entire TIM. The terminal extracts the block bitmap which indicates which blocks contain data, and the page index which identifies the relevant page, allowing it to skip decoding unnecessary blocks and enter power save mode when no data is present.
Solution Approach 2:
The patent applies partial action by performing only the minimum necessary decoding operations. Instead of fully decoding all TIM blocks, the terminal performs partial decoding of just the block bitmap and page index fields, which are sufficient to determine whether data transmission is present. This partial decoding approach reduces power consumption while maintaining reliable detection capability.
2Device complexity
If block positions are determined sequentially from fixed position, then decoding process is simplified, but decoding time increases when blocks have variable lengths
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the offsets of block controls from the beginning of the partial virtual bitmap. These offsets are prepared in advance and stored in a table, allowing the terminal to directly access any block control position without sequential decoding. When needed, the terminal can immediately jump to the required block using the pre-computed offset, significantly reducing decoding time while keeping the decoding logic simple.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a method of communicating encoded traffic indication map (TIM) information that can reduce power consumption by reducing an unnecessary decoding process. A method of receiving, by a terminal, a TIM that is encoded in a hierarchical structure including a page, a block, and a sub-block includes receiving an encoded TIM from an access point (AP), extracting a page index from the encoded TIM, and extracting block bitmap information indicating whether blocks included in a page designated by the page index include a bitmap. Therefore, an unnecessary decoding process with respect to each delivery traffic indication map (DTIM) beacon can be reduced, thereby reducing power consumption of a low-power terminal.