Uplink Congestion Control via SIP Exponential Backoff

The patent implements periodic action by introducing exponential backoff mechanisms where user equipment devices retry SIP registration requests at progressively longer intervals. When congestion is detected, devices wait for exponential backoff periods before attempting reconnection, transforming continuous simultaneous connection attempts into periodic, staggered actions that prevent RAN and IMS uplink congestion while maintaining service capacity.

The patent applies feedback by implementing congestion detection mechanisms that monitor SIP registration request rates and trigger provisional response codes (429 Too Many Requests) when thresholds are exceeded. This feedback loop allows the network to detect congestion conditions and dynamically adjust device behavior through standardized SIP messaging, preventing service disruptions while maintaining high service capacity.

The patent addresses synchronous device reboots during power outages by implementing periodic action through exponential backoff. When devices detect network unavailability and attempt reconnection, the backoff mechanism spreads out these reconnection attempts over time rather than allowing simultaneous processing, thereby preventing uplink congestion and resource exhaustion even during resilience-critical events like power outages.

The patent applies beforehand cushioning by pre-configuring devices with backoff timers and congestion control parameters that activate automatically during stress events. This cushioning mechanism is prepared in advance but only activates when needed, protecting the network from synchronous reboot storms without affecting normal operation, thus maintaining service resilience while preventing harmful uplink congestion.

The patent resolves the contradiction between quick processing and congestion by implementing periodic action through exponential backoff. Instead of processing all SIP registration requests simultaneously, the system introduces deliberate time intervals between retry attempts. This transforms the quantity of concurrent requests from high (causing congestion) to managed (maintaining availability), allowing service access while controlling congestion volume.

The patent applies parameter changes by dynamically adjusting retry timing parameters based on network conditions. When congestion is detected through SIP rate monitoring, the system changes the retry interval parameter from immediate or fixed to exponential backoff values. This parameter adjustment reduces the quantity of simultaneous requests (congestion volume) while preserving service availability through systematic retry mechanisms.