Amtrak will ditch cellular backhaul for its upgraded Wi-Fi service
Amtrak is taking a new approach to solve problems with its widely mocked Wi-Fi service. The railroad service is soliciting bids for a dedicated trackside wireless broadband network that will backhaul Wi-Fi service for Amtrak's Acela Fleet, the high-speed rail service along the Northeast Corridor (NEC) between Washington, D.C., and Boston.
Amtrak said in a statement of work (SOW) document that the complete technical solution will comprise three key elements: connection to the on‐board network (OBN) on the trains; the trackside network (TSN) in or near the wayside; and a back-office operational support system (OSS) for equipment and service monitoring and management.
While the train‐to‐ground connection will deliver network traffic between the train and the wayside, that traffic will then be routed to the network backbone, which Amtrak said might be a fiber link at the wayside radio site or a second wireless connection, such as a microwave link, to the nearest fiber connection point. "The primary purpose of the TSN is to facilitate the delivery of a high‐speed connection between a train and the wayside, and route that connection's network traffic to the fiber backbone and then to the Internet," Amtrak said.
One potentially tricky aspect of the planned trackside deployment is that it will have to interoperate with existing OBNs on the trains because the new trackside network will be installed in phases over time. Those OBNs provide Wi‐Fi service to passengers and are backhauled via concurrent cellular links over multiple cellular networks.
In fact, problems with those OBNs are what led Amtrak to seek a new solution. Passengers have derided the railroad's Wi-Fi service since its introduction, with slow speeds and dropped service being the main complaints.
The existing service "is constrained by factors including but not limited to availability of contiguous data network coverage along the ROW [right of way]; downlink and uplink capacity available to the OBN over these networks; the physical distance of cellular base stations from the ROW; and contention on cellular base stations from off‐train users and their devices," Amtrak said.
"The purpose of the TSN is to mitigate these factors by replacing the cellular links with a private, dedicated network that shall significantly improve the quality and performance of the train‐to‐ground connection," it added.
Amtrak noted the new train‐to-ground network will need to deliver sustained downlink throughput of at least 25 Mbps per train at train speeds up to 160 miles per hour and will be required to scale to over 100 Mbps per train by 2019. To serve multiple trains running along the Northeast Corridor concurrently, Amtrak has pledged to provide a fiber backbone with a minimum of 1 Gbps of backhaul connectivity, scaling to at least 3 Gbps by 2019.
Northeast Corridor ridership in 2013 reached some 11.57 million travelers, up 2 percent over the prior year. Amtrak expects ridership will exceed 13 million passengers by 2019.
"The existing Wi‐Fi service has a user uptake rate of 50 percent or more, and this is expected to increase as more riders use Amtrak trains in the future. As a result it is critical to not only deliver sufficient broadband capacity to trains to meet user demand, but to implement a system that will scale over time and facilitate a wider range of user needs including but not limited to streaming media," Amtrak said.
The closing date for proposals is July 28, 2014, but those planning to submit proposals must attend a pre-proposal conference and site visit on June 18.