Now that Mobile World Congress 2013 in Barcelona has come to a close, our main takeaway, particularly with regard to mobile infrastructure, is that the industry continues to move forward in its thoughts and plans to address increased bandwidth needs and drive revenue from the networks with value added services. The most widely discussed topics at the show centered on small cells, LTE and cloud.
Small Cells: Large Scale Rollouts Will Happen, Albeit Slowly
There were extensive discussions among operators and vendors about the current status of small cell deployment and related issues. The word small cell often includes residential and enterprise femtocells, which have been deployed in large volume. However, we refer here to public access small cells, which most operators agree are important to increase network capacity once basic 4G/LTE coverage has been addressed. However, only very limited roll outs are expected over the next year. It was clear that many technology issues related to large-scale deployment of these public access small cells are still open including the capex and opex of backhaul, providing accurate network timing to these small cells, interference mitigation, preference to use licensed vs. unlicensed spectrum, Line-of-Sight vs. Non-Line-of-Sight, etc. Despite this, our conclusion is that operators see small cells as a critical part of their future direction and the large-scale roll out will happen, albeit slowly.
Small Cell Backhaul: Ethernet/IP Is The Only Way To Go
There were several interesting announcements about small cell backhaul platforms operating over various mediums, including copper, fiber, microwave and millimeter-wave. For example, the Alcatel Lucent 7705 SAR-W, Tellabs 8602 and Fibrolan Falcon series targeted small cell backhaul over copper and fiber. The ALU and Tellabs platforms are part of the larger service router product family, while Fibrolan’s is a dedicated small cell backhaul platform with CE 2.0 support and options for caching to handle video traffic optimally. NEC, Bridgewave, Ceragon, Fastback Network and Tarana Wireless launched new platforms for microwave and millimeter wave backhaul with some interesting innovations addressing bandwidth scaling, space constraints, non line of sight and timing distribution issues.
In spite of different approaches, the common theme was packet-based (Ethernet/IP) backhaul. This may be old news to some. But our observation from MWC was that OEMs concur that other backhaul technologies such as T1/E1 are disappearing fast and Ethernet/IP is definitely the only way to go for small cells. Layer-2 versus Layer-3 networking for small cell backhaul is still an open discussion, ranging from related complexity of a L3 network at the network edge to the Layer-3 tools to manage a network with many nodes.
LTE and LTE-A: Network Timing is Critical
By now, LTE is a given as the future of mobile networks. But there were even some interesting LTE-Advanced (LTE-A) deployment announcements from Telstra and NTT Docomo by 2015. Both TD-LTE and LTE-A bring challenging timing requirements to the forefront. In conversations around MWC, it is clear that IEEE1588v2 (1588) is widely accepted as a requirement for packet-based backhaul networks. Even in the US, it is seen as a backup to the GPS based timing, in particular since GPS is not reliable at street level due to lack of satellite line-of-sight and susceptibility to jamming and spoofing. Some 1588 deployments are already underway. But the network based deployment model that can support 1588 phase accuracy required by LTE-A, is still a topic of heavy debate. Vitesse has provided some insights to an approach in the recently published white paper – Precise Timing for Base Stations in the Evolution to LTE
Cloud RAN and M2M
Finally, the topics of Cloud RAN and M2M networking were discussed by only a few vendors. But we expect these topics to gain more prominence over the next year and look forward to more discussions on these subjects in future events.