Whitespace Map Version Bit Reduces Channel Acquisition Time
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Solution Overview
Problem
Unlicensed users in wireless communication systems face challenges in efficiently accessing available channels in whitespace bands without causing interference to licensed users, as they currently require extensive time and resources to acquire channel information.
Innovation Solution
A method is introduced where a whitespace map (WSM) information is transmitted with a predetermined map version bit value for informative purposes, allowing unlicensed devices to quickly identify available channels and transmission power constraints, thereby reducing the time needed to determine available channels and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If unlicensed devices access geo-location database through Internet or dedicated network to obtain channel information, then they can identify available channels, but it consumes extensive time and network resources
Solution Approach 1:
The system performs preliminary action by having the enabling STA (access point) pre-acquire WSM information from the geo-location database and store it locally. The dependent STA (client device) can then obtain this pre-prepared channel information through local wireless communication without needing to access the database directly, thus saving time and network resources.
Solution Approach 2:
The enabling STA acts as an intermediary between the geo-location database and the dependent STA. It retrieves channel availability information from the database on behalf of client devices and distributes this information wirelessly, eliminating the need for each device to independently access the database through the Internet.
2Reliability
If unlicensed devices perform spectrum sensing mechanism or access GDB frequently to protect licensed device, then licensed device protection is ensured, but device complexity and resource consumption increase
Solution Approach 1:
The system extracts the complex GDB access and spectrum sensing functions from individual dependent STAs and consolidates them in the enabling STA. The access point alone performs database queries and maintains channel availability information, while client devices simply receive pre-processed WSM information, significantly reducing the complexity burden on each device.
Solution Approach 2:
The enabling STA performs multiple functions: it acts as a wireless access point for data communication, a geo-location database client for channel information acquisition, and a WSM distribution server for informing dependent STAs about available channels. This multi-functionality consolidates complexity in a single device rather than requiring each device to perform all functions.
3Loss of time
If WSM information is transmitted to all STAs for informative purpose, then unlicensed devices can quickly identify available channels, but transmission overhead increases
Solution Approach 1:
The system applies local quality by transmitting WSM information with a specific map version bit value (e.g., 127) that indicates informative purpose only. Dependent STAs recognize this special value and store the information locally without triggering unnecessary updates or transmissions, optimizing energy usage based on the specific needs of each device.
Solution Approach 2:
The system uses partial action by transmitting WSM information selectively - when the map version bit indicates informative purpose, the information is provided for reference without requiring full processing or update cycles. This partial transmission approach reduces overall overhead compared to complete WSM updates while still providing timely channel information.
Data Source
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AI summary
The present invention relates to a wireless communication system, and more specifically, to a method and apparatus for transmitting and receiving a whitespace map. The method for transmitting whitespace map (WSM) information from a first station (STA) to a second STA includes the steps of: setting a map version bit value included in the WSM information as a predetermined value; and transmitting the WSM information including the predetermined map version bit value to the second STA.