For most operators moving from 2G networks to advanced 3G and 4G networks, this migration is an evolution that will take place over time. This means the majority of network operators will keep their existing 2G services up and running while they add advanced 3G and 4G networks to handle data traffic growth.
Combining TDM/Sonet/SDH and Ethernet into a single device, P-OTS offers an ideal bridge for network operators taking a stepped approach to Ethernet backhaul. With P-OTS, an operator can continue to run its 2G traffic using Sonet/SDH while growing its high-speed data traffic using native Ethernet. As the traffic and service mix shifts more and more from 2G to 4G, the P-OTS elements can be configured to match the changing mix. Furthermore, P-OTS presents operators with an interesting new combination: connection-oriented Ethernet over Sonet/SDH transport, or COEoS. This new twist combines the statistical multiplexing efficiencies of Ethernet with the trusted resiliency and reliability of Sonet/SDH transport.
Where telco TV drove a lot of development in metro core P-OTS, we are seeing the mobile backhaul application driving development in edge/aggregation and access P-OTS systems. Thus, the International Telecommunication Union, Standardization Sector (ITU-T) 's Synchronous Ethernet and the Institute of Electrical and Electronics Engineers Inc. (IEEE) 's 1588v2 standards for timing and synchronization in packet networks are key functionalities on emerging access and edge/aggregation P-OTS systems. Why is this needed on a system that already has native Sonet/SDH functionality? Eventually, operators will want to run their TDM cell traffic over the Ethernet network, and P-OTS systems must be as competent in this respect as the Layer 2/3 switch equipment with which they will increasingly compete.
Mobile backhaul for P-OTS is not without its challenges. In our research for this report, we found that a general lack of awareness of the packet-optical transport option may be the biggest hurdle – keep in mind, this equipment is very new. Based on our global operator surveys, we know that operators view Sonet/SDH MSPPs as a no-go for Ethernet backhaul networks, because EoS won't scale. The problem for P-OTS suppliers is that they may be getting lumped into the Sonet/SDH bucket and, therefore, excluded in the running for next-gen backhaul bids.
In addition, P-OTS will compete primarily with Layer 2/3 switches for mobile backhaul business. Here, the onus is on the P-OTS suppliers to match Layer 2/3 switch functionality and (just as importantly) prove to operators that their packet abilities are just as good as those of the pure packet players.
With these challenges met, mobile backhaul could become the "killer app" for P-OTS.
— Sterling Perrin, Senior Analyst, Heavy Reading
For more information about Heavy Reading's "The Future of Packet-Optical Transport for Mobile Backhaul," or to request a free executive summary of this report, please contact:
- Dave Williams
Sales Director, Heavy Reading