Traffic Indication Map Encoding for Beacon Frame Byte Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In WLANs, the existing methods for generating Traffic Indication Maps (TIM) in beacon frames are inefficient, leading to long generation times and large byte occupancy, especially when the number of user terminals with cached data is close to those without, or when association identifiers are far apart, resulting in excessive time and resources needed for transmitting these frames.
Innovation Solution
The proposed encoding method for TIMs and beacon frames controls the display of sub-block bitmap fields by marking bits in a bitmap control field, allowing user terminals to determine if data is cached or if they should access a channel, thereby reducing the byte occupancy of TIMs by selectively hiding or displaying sub-block bitmap fields based on specific thresholds and identifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the access point generates a complete TIM bitmap for all user terminals, then all user terminals can accurately determine whether data is cached, but the TIM occupies large byte space and requires long transmission time
Solution Approach 1:
The patent divides the TIM bitmap into multiple sub-bitmaps, each corresponding to a specific user terminal or group of terminals. Each sub-bitmap contains only the relevant bits for that terminal, allowing selective transmission of only the necessary portions based on which terminals have cached data, thus reducing overall transmission time while maintaining accuracy for each terminal.
Solution Approach 2:
The patent dynamically adjusts the TIM structure by marking certain bits in the bitmap control field to indicate whether specific sub-bitmaps should be displayed or hidden. This dynamic adaptation allows the access point to optimize the TIM size based on current cache status, transmitting only the necessary information for terminals with cached data while suppressing unnecessary sub-bitmaps to reduce transmission time.
2Loss of information
If the access point includes all sub-block bitmap display fields in the TIM, then complete information is provided for all user terminals, but the byte occupancy increases significantly
Solution Approach 1:
The patent extracts and removes unnecessary sub-block bitmap display fields from the TIM based on the cache status of user terminals. By identifying which terminals have cached data and only including sub-bitmaps for those terminals, the patent reduces the byte occupancy of the TIM while ensuring that all necessary information for terminals with cached data is still完整地 provided.
Solution Approach 2:
The patent uses dynamic marking in the bitmap control field to adaptively control which sub-block bitmap display fields are included in the TIM. This dynamic adjustment allows the TIM size to vary based on current network conditions and cache status, reducing byte occupancy by excluding unnecessary fields while maintaining information completeness for relevant terminals.
3Reliability
If user terminals are spaced far apart in association identifier sequence, then each terminal has unique identification, but the TIM generation time increases due to large distance coverage
Solution Approach 1:
The patent segments the TIM generation process by creating separate sub-bitmaps for different user terminals based on their association identifiers. This segmentation allows the access point to generate and process each terminal's information independently and in parallel, avoiding the need to sequentially process large gaps in association identifier sequences, thus improving TIM generation efficiency while maintaining accurate identification.
4Measurement precision
If the TIM includes detailed information for all user terminals, then accurate data availability determination is enabled, but the beacon frame transmission requires excessive time
Solution Approach 1:
The patent implements dynamic control of TIM content by using marking bits in the bitmap control field to indicate which sub-block bitmap display fields should be included. This dynamic adaptation allows the TIM to contain detailed information only for terminals that actually have cached data, maintaining measurement precision for data availability determination while significantly reducing beacon frame transmission time by excluding unnecessary detailed information for terminals without cached data.
Data Source
AI summary
Embodiments of the present disclosure provide an encoding method for a traffic indication map and a beacon frame, which relate to a communication field, enable a user to know whether there are data cached in an access point or enable a user terminal to know whether to access to a channel, and reduce the quantity of bytes occupied by the traffic indication map in the beacon frame. The encoding method for a traffic indication map provided by the embodiments comprises: controlling whether to display a sub-block bitmap display field in a sub-bitmap by marking at least one bit in a bitmap control field, a sub-block sub-bitmap in the sub-bitmap being used for enabling a user terminal to know whether there are data cached in an access point, or enabling the user terminal to know whether to access to a channel.