In today’s fast-paced telecommunications world, service providers must keep up with the growing demand for ultra-high bandwidth. As fibre owners, they need to meet the increasing needs of their current and future customers while managing the complexities of existing infrastructure.
The challenge is optimising the current network. This becomes tricky when using standard dual-fibre optical transceivers while trying to add more customers without resorting to expensive and time-consuming measures like trenching additional fibre, deploying technical teams, or undertaking complex field replacements.
In this blog, we’ll explore innovative solutions to meet the evolving needs of communication service providers (CSPs) and their customers.
What is a BiDi SFP?
Modern optical transceivers use two fibres to transmit data between devices like switches, firewalls, servers, and routers. One fibre receives data from network equipment, and the other fibre transmits data to it.
However, BiDi (bi-directional) transceivers can transmit and receive data through a single optical fibre. This technology uses wavelength division multiplexing (WDM) couplers (diplexers) to combine and separate data based on light wavelengths. Hence, BiDi transceivers are also called WDM transceivers.
BiDi transceivers must be used in matched pairs, with their diplexers tuned to the expected wavelengths of the intended transmitter and receiver.
For example, if you’re connecting Device A (upstream) and Device B (downstream) with paired BiDi transceivers:
- Transceiver A’s diplexer will have a receiving wavelength of 1490nm and a transmitting wavelength of 1310nm.
- Transceiver B’s diplexer will have a receiving wavelength of 1310nm and a transmitting wavelength of 1490nm.
Passive BiDi Transceivers
RAD has developed a patented BiDi QSFP adapter to facilitate the transition from dual-fiber to single-fiber transceivers. This passive, small-form adapter can be plugged into existing SFPs, providing immediate savings for 1G, 10G, 100G, and 200G fiber infrastructure without replacing the installed SFPs or facing interoperability issues.
For 1G and 10G SFPs, RAD’s BiDi QSFP adapter performs with minimal range degradations—up to 80 km (50 miles) for 1G and 40 km (25 miles) for 10G. For 100G QSFPs, RAD’s BiDi is effective up to 25 km (15.5 miles).
The Benefits for Service Providers Are Twofold
Network Link Capacity Expansion
When building transmission networks, the scale of optical cables is planned based on the expected business volume and fibre core ratio. However, with the increasing number of fibre users, optical cable core resources are becoming scarce. Constructing new optical fibres is costly and time-consuming. By reducing the number of fibres per customer, CSPs can quickly expand network link capacity and save on construction costs.
Enhanced Network Link Maintenance
Maintenance and repair time is significantly reduced if a fibre link in a single-fibre bidirectional transmission system is interrupted. This is because the number of fibres requiring maintenance is halved compared to traditional dual-fibre systems.
In Summary
Increasing network capacity without trenching new fibres can be addressed by replacing traditional SFPs with BiDi capabilities. However, due to the active nature of SFP devices, this switch might cause interoperability issues and service downtime. A better solution is a passive optical device that redirects light from dual-fibre SFPs to single-fibre, doubling fibre capacity without replacing SFPs.
While BiDi transceivers offer significant cost savings in fibre cabling infrastructure, some service providers might hesitate due to operational constraints. RAD’s BiDi QSFP adapter presents an accessible, cost-effective alternative, ensuring high-performance service delivery up to 200G.
