LTE Positioning Protocol Message Segmentation for PDCP Limits
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Solution Overview
Problem
The size of positioning protocol messages, such as LPP messages, often exceeds the size limit imposed by transport protocols like PDCP, leading to potential failures or impaired location estimates in wireless communication systems, as they cannot be fully transmitted or result in lower accuracy due to incomplete data.
Innovation Solution
Implementing message segmentation for positioning protocol messages, where large messages are divided into smaller segments, each being a well-formed message with a subset of the information, and using capability flags to indicate support for segmentation, ensuring the receiver waits for all segments before processing, thus maintaining message integrity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If positioning protocol messages are transmitted using standard transport protocols, then message transmission is straightforward, but messages exceeding size limits cannot be transmitted or result in impaired location estimates
Solution Approach 1:
The patent divides large positioning protocol messages into multiple smaller segments that can be transmitted individually through the transport protocol. Each segment is a well-formed message containing a subset of the original information, allowing reliable transmission of data that would otherwise exceed size limits. The receiver reassembles the segments to reconstruct the complete message.
2Reliability
If large positioning messages are segmented into smaller parts, then transmission reliability improves, but message complexity and processing overhead increase
Solution Approach 1:
The patent includes capability flags in the positioning protocol messages that indicate in advance whether segmentation is supported by the transmitting and receiving devices. This preliminary indication allows the system to prepare appropriate handling procedures before segmentation occurs, reducing processing complexity during actual message transmission and reception.
Solution Approach 2:
The patent uses capability flags as a form of feedback mechanism where devices communicate their segmentation support status beforehand. This feedback allows the system to adapt its message handling approach, ensuring that segmentation is only applied when both transmitting and receiving devices are capable, thereby managing complexity effectively.
3Speed
If the receiver processes segmented messages immediately upon receipt, then processing speed increases, but location estimate accuracy deteriorates due to incomplete data
Solution Approach 1:
The patent implements a waiting mechanism where the receiver holds off on processing positioning messages until all segments have been received and reassembled. This preliminary completion check ensures that location estimate calculations are based on complete data, maintaining accuracy while still enabling efficient processing once the data is complete.
Data Source
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AI summary
Methods and techniques are described for limiting a size of LTE Positioning Protocol (LPP) messages in a location session between a user equipment and location server. In one embodiment, a first device sends a first LPP message to a second device, indicating that the first device is capable of receiving segmented LPP messages. Subsequently, the first device receives a plurality of LPP message segments from the second device comprising one or more non-final LPP message segments and a final LPP message segment, where each LPP message segment includes a "non-final" or "final" indication. The first device stores the non-final LPP message segments and processes the LPP message segments after receiving the final LPP message segment. Prior to sending the first LPP message, the first device may receive an LPP message from the second device indicating the second device is capable of sending segmented LPP messages.