LTE Coexistence via A-priori Uplink Scheduling
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Solution Overview
Problem
Conventional LTE systems face coexistence issues due to interference between LTE uplink signals and Bluetooth or WLAN signals, particularly in the Industrial Scientific and Medical (ISM) band, leading to unacceptable error rates and disruptions in voice services, as the eNB is not adequately aware of uplink interference, resulting in unresolved coexistence problems and performance degradation.
Innovation Solution
A method and apparatus for wireless communication that receive an indication of time and frequency resources of future activity of a mobile wireless service (MWS) radio access technology via physical layer communication, allowing scheduling of communications to coordinate behavior and reduce interference between MWS and Wireless Connectivity Network (WCN) radio access technologies, such as LTE and Bluetooth/WLAN, by utilizing the timing of scheduling MWS communications to improve coexistence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LTE uplink transmissions are performed simultaneously with Bluetooth or WLAN in the ISM band, then LTE communication functionality is maintained, but interference occurs causing unacceptable error rates and voice service disruptions
Solution Approach 1:
The system performs preliminary actions by having the eNB send uplink grant messages to the UE in advance, providing ahead-of-time information about scheduled uplink transmissions. This advance notice allows the UE to proactively manage coexistence with other radios (Bluetooth, WLAN) by scheduling their operations to avoid interference with the predetermined LTE uplink transmissions, thereby maintaining reliable communication across multiple radios.
2Productivity
If the eNB uses RSRP reports to make handover decisions, then network optimization is achieved, but ping-pong effects occur when the UE unilaterally moves to a different frequency channel to avoid interference
Solution Approach 1:
The system implements feedback by having the UE report interference conditions and coexistence issues to the eNB. The eNB uses this feedback information to make informed handover decisions that account for both RSRP measurements and actual interference conditions. This feedback loop prevents ping-pong effects by ensuring the network has complete information about the UE's interference environment when making connection management decisions.
Solution Approach 2:
The uplink grant message acts as an intermediary mechanism that conveys scheduling information from the eNB to the UE. This intermediary provides the UE with advance knowledge of upcoming uplink transmissions, enabling the UE to make informed decisions about frequency channel selection and coexistence management with other radios, thereby stabilizing connections and preventing unnecessary handovers.
3Reliability
If the UE unilaterally re-establishes connection on a different frequency channel to avoid interference, then temporary interference avoidance is achieved, but the eNB may handover the UE back to the original corrupted channel, causing ping-pong effects
Solution Approach 1:
The eNB performs preliminary action by sending uplink grant messages that inform the UE of scheduled uplink transmissions in advance. This allows the UE to proactively plan its frequency channel usage and coexistence strategy with other radios before interference occurs, rather than reacting unilaterally after interference has started. The advance scheduling information enables coordinated frequency management that prevents the need for repeated channel changes and handovers.
Data Source
AI summary
A user equipment (UE) uses information regarding the timing of scheduling mobile wireless services (MWS) RAT communications to improve MWS and wireless network connectivity (WCN) radio access technology coexistence. To allow sufficient time for an uplink grant to be received by the UE in advance of the scheduled uplink time, an uplink grant may be sent in advance of the scheduled uplink time. In some instances, the UE may receive an indication of scheduled uplink time of the MWS RAT via a physical layer communication. The UE may schedule communications of the WCN RAT based at least in part on the indication of future activity.