Overview of Bit-Error-Triggered Protection Switching

Definition

A bit error refers to the deviation between a bit that is sent and the bit that is received. Cyclic redundancy checks (CRCs) are commonly used to detect bit errors. Bit errors caused by line faults can be corrected by rectifying the associated link faults. Random bit errors caused by optical fiber aging or optical signal jitter, however, are more difficult to correct. Bit-error-triggered protection switching is a reliability mechanism that triggers protection switching based on bit error events (bit error occurrence event or correction event) to minimize bit error impact.

Purpose

The demand for network bandwidth is rapidly increasing as mobile services evolve from narrowband voice services to integrated broadband services, including voice and streaming media. Meeting the demand for bandwidth with traditional bearer networks dramatically raises carriers' operation costs. To tackle the challenges posed by this rapid broadband-oriented development, carriers urgently need mobile bearer networks that are flexible, low-cost, and highly efficient. IP-based mobile bearer networks are an ideal choice. IP radio access networks (IPRANs), a type of IP-based mobile bearer network, are being increasingly widely used.

Traditional bearer networks use retransmission or the mechanism that allows one end to accept only one copy of packets from multiple copies of packets sent by the other end to minimize bit error impact. IPRANs have higher reliability requirements than traditional bearer networks when carrying broadband services. Traditional fault detection mechanisms cannot trigger protection switching based on random bit errors. As a result, bit errors may degrade or even interrupt services on an IPRAN.

To solve this problem, configure bit-error-triggered protection switching.

To prevent impacts on services, check whether protection links have sufficient bandwidth resources before deploying bit-error-triggered protection switching.

Benefits

Bit-error-triggered protection switching offers the following benefits:

• Protects traffic against random bit errors, meeting high reliability requirements and improving service quality.

• Enables devices to record bit error events. These records help carriers locate the nodes or lines that have bit errors and take corrective measures accordingly.