Researchers at the University of New South Wales are developing an intelligent wireless protocol for public transport networks, which will give passengers cheaper online access and lower power consumption.
Called OCEAN (On-board Communication Entertainment and Information), the protocol can be embedded in chips and placed on board buses and trains, allowing the vehicles to create a communication network.
Associate Professor Mahbub Hassan, of the School of Computer Science and Engineering, said the most similar technology that's currently available is Cisco's recently released general-purpose 3200 Series Wireless and Mobile Router that can be embedded in a vehicle.
"But it does not have all the intelligence that we are developing in the OCEAN project, and our project is not about designing a router, but an integrated solution for efficient information access on-board public transport," he said.
Other protocols available
Hassan said the protocol is superior to other mobile wireless Internet services currently available, such as iBurst or Unwired, because it is based on an onboard mobile router, which acts as a gateway between the passengers and the global Internet, or passengers in other buses or trains.
"The distance between a passenger's device and the onboard mobile router is very short, so therefore is much less taxing on battery power," Hassan said.
"If other services were used, the passenger devices would need more power to connect to a distant wireless base station outside the bus or train, and this would deplete the battery much quicker."
Low cost is another advantage, Hassan said.
"If all buses and trains cooperate in relaying data to each other, the cost of communication can be very low compared to other wireless services, so that the bus company could even provide a free, online service to its passengers," he said.
He admitted that the wireless service providers may not like this idea.
The more the merrier
iBurst spokesperson John Filmer does not see this protocol as potential competition.
"These types of initiatives are excellent for raising awareness of and supporting mobile wireless," he said.
"[In fact] this type of application or protocol sounds like something iBurst could handle and now that iBurst has been ratified as a standard by the American National Standards Institute (ANSI), that gives us even more scope. So unless there are any aspects of the protocol that I am not aware of, we would be happy to discuss it further with the developers," he said.
Unwired CTO, Eric Hamilton, was similarly optimistic.
"I think it is a neat idea, because it makes best use of resources that are around, rather than having, say 20 people connect to the same location by different means. It is using the spectrum to best effect. At the end of the day customers can always choose which mechanism of connection to use anyway, so it just gives them another option. Competition is always good," he said.
In addition to competition it creates cooperation, he said.
"The probabilities are very high that in the future people will have devices that can connect into any number of networks and it may depend on their location, or on the type of content they want to send or receive, or it may depend on their own personal preferences."
Speed is the key
The service is capable of delivering tens of Mbit/s when it is relaying data between buses that are close by. When there are no buses close, the mobile router can connect via cellular services, such as Vodafone or Telstra's 3G services that would give a minimum of 384 kbit/s.
"In fact, the on-board mobile router could also use the services of iBurst or Unwired to achieve high data rate. Passengers still connect to the on-board mobile router to [get] online, and don't really care how the mobile router provides the online connectivity," Hassan said.
Intelligent features of the service include Wireless Multihop, where each vehicle would have a small routing device that 'talks' to any other vehicle passing by. As one vehicle passes, the commuter's computer automatically connects with the next one passing by.
"Our intelligent protocols can learn from previous histories, when buses or trains are coming that they can connect with. They can even allow for delays in traffic," Hassan said.
Another intelligent aspect called semantic compression aims to avoid network congestion by dynamically profiling the user. It determines the type of material the user normally accesses and then filters their Internet search so that only the most relevant data pops up.
Although using a TCP/IP network on board a vehicle with a mobile router providing connectivity to the global Internet may sound simple, Hassan said there are many networking and data management challenges that need to be resolved for on-board mobile computing to really take off.
Errors affect large numbers
"For example, any error or outage in the wireless link will immediately affect a large number of users. Additionally, link outages in such systems can be frequent and long lasting such as when a train is going in and out of tunnels," he said.
"Secondly, traffic from large numbers of users can easily overwhelm the wireless link. Also, the population of the network is very dynamic. Passengers are getting on and off the vehicle all the time. Caching or hoarding data and providing personalized delivery of relevant information for such a dynamic user base is a challenging task," he said.
It is a task though that the three associate professors, one postdoctoral researcher and two PhD research students are eagerly taking on after receiving funding of A$300,000 primarily from the Australian Research Council. Their research is expected to be completed by the end of 2006.
"If we can successfully develop the required algorithms and methods, further resources will then be needed for prototyping, and collaboration will be needed with Sydney buses or trains for trials," he said.
Hassan said the technology would help encourage people to catch public transport.
"There are also other benefits. On-board communication infrastructure, for example will enable remote video surveillance of public transport vehicles leading the way to unprecedented passenger safety and security," he said.