BellSouth does not look at the optical part of its network in a vacuum. It is just one part of an interconnected network, said Bill Smith, Chief Product Development and Technical Officer of Bell South, speaking at OFC's Service Provider Summit in Atlanta this week. While it would be nice to create an all-new network on a fresh sheet of paper, reality requires a mix of solutions that integrate old and new, DSL, fiber and wireless. In addition, Smith said the ongoing operation of all network elements is more difficult than the initial rollout of equipment, requiring an integrated view of network planning and management. Smith described the on-going transformation of BellSouth's network to packet services, which will ultimately be delivered through MPLS, network-based IP-VPNs, and metro Gigabit Ethernet. Packet voice is developing through Internet Call Diversion (ICD), Packet Voice Tandem (PVT), VoIP, and IP Telephony Gateway (IPTG) technologies. Key optical advances for BellSouth include OC-192 MSPPs, wavelength services, and further rollouts of fiber to the business. Smith noted that BellSouth just completed deployment of an optical high performance core, which has reduced end-to-end latency from 100 to 20 ms across the carrier's entire region. In addition, key Internet access points have been reduced from nine to four, which Smith predicts will be helpful when confronting major viruses and worms like the recent Slammer virus. Future optical network upgrades will include OEO digital cross connects to address the complications, opportunities for failure, and difficulty of provisioning SONET networks. In addition, certain SONET networks will be upgraded to DWDM and systems will be deployed to offer metro Gigabit Ethernet and wavelength services. Smith also believes that disaster recovery and mainframe and off-site backup services could be very popular. Smith also shared several thoughts about the evolution of the access network.
- Delivery of voice, video and high-speed data on an integrated network is now a requirement.
- DSLAM deployments will take place deeper in the network
- As services evolve, the customer interface should change as little as possible. For instance, if BellSouth rolls out FTTH, there should be no need for customers to change their in-house wiring.
- Entertainment services via DSL are more promising than ever before. BellSouth's content partners now say that they need only 3 Mbps to deliver video. Breaking news and live sporting events need to be viewed in real time -- other programming can be delivered through personal video recorders.
- VDSL has great potential in multi family units. However, for neighborhoods of single-family homes, it is not clear that fiber reaches close enough to make VDSL viable. If fiber has to be run in closer, it might be better to go all the way to FTTH.
- PON has some appeal. The technology looks good, but pricing has not declined to where it needs to be. PON will be most likely used in greenfield and overbuild situations.
- Fixed wireless provides a good fill-in strategy, perhaps in rural areas and other places where DSL and FTTH do not make sense. BellSouth is now running a trial with Navini's fixed wireless system.
Smith observed that while service providers are constantly dealing with the challenging integration of multiple functions in the network, he is concerned that many system vendors are proposing solutions that try to accomplish too much in a single "god box style" platform. Instead, he feels that it may be better to have a more straightforward platform with just the key features. These are generally easier to implement and less expensive.
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