Adaptive NAS Timer Extension for Extended Coverage Wireless Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cellular systems face challenges in extended coverage areas, such as basements or underground locations, where radio signals suffer from severe attenuation, leading to increased signalling latency and battery consumption due to timed-out procedures in mobile stations operating in extended coverage scenarios.
Innovation Solution
The method involves extending NAS timers in communication devices and core network nodes based on the coverage capability, using coverage classes to determine extended time periods for signalling messages, thereby reducing the risk of failures and unnecessary delays in both extended and non-extended coverage scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard NAS timers are used in extended coverage areas, then the system maintains standard timing operations, but signalling procedures time out due to increased latency
Solution Approach 1:
The patent applies dynamics by making the NAS timer values adaptive rather than fixed. The network node determines extended NAS timer values dynamically based on the coverage class of the communication device, allowing the timer to adjust to different propagation delay conditions in extended coverage areas versus standard coverage areas.
Solution Approach 2:
The patent changes the parameter of timer duration based on coverage conditions. By determining extended NAS timer values that are longer than standard timer values when operating in extended coverage areas, the system accommodates increased signalling latency while maintaining procedure completion reliability.
2Reliability
If extended NAS timer values are used in extended coverage areas, then the risk of timeout failures is reduced, but unnecessary delays occur in non-extended coverage scenarios
Solution Approach 1:
The patent applies local quality by implementing different timer values for different operational contexts. The network node determines whether the communication device is operating in extended coverage or standard coverage and applies appropriate timer values locally to each scenario, ensuring optimal performance for each condition.
Solution Approach 2:
The system dynamically adjusts timer values based on real-time coverage conditions. The network node determines the coverage class and selects appropriate NAS timer values, making the timing parameters adaptive to current operational conditions rather than using a fixed extended value in all cases.
3Use of energy by moving object
If standard timer values are used for signalling procedures, then the system operates with standard timing, but battery consumption increases due to repeated timeout and retransmission
Solution Approach 1:
The patent applies beforehand cushioning by pre-determining extended NAS timer values that account for potential propagation delays in extended coverage areas. This prevents timeout failures before they occur, eliminating the need for repeated retransmissions and associated battery consumption.
Solution Approach 2:
The patent eliminates the need for expensive battery consumption by using appropriate timer values from the start. By determining extended NAS timer values that prevent timeouts, the system avoids the costly (in terms of battery energy) cycle of timeout-failure-retransmission that would otherwise occur with standard timer values.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method performed by a communication device for determining an extended time period related to a signalling message between a core network node and the communication device in a wireless communications network, the method comprising: obtaining (301) an indication of a coverage capability of the communication device; obtaining (302) an indication of a time period, which time period is related to the signalling message; and determining (303) the extended time period related to the signalling message, based on the indication of the coverage capability of the communication device and based on the indication of the time period.