A metal tube travelling through the sky at hundreds of miles per hour may not be a natural environment for wireless communications but, increasingly, travellers are demanding access to the bandwidth that they have become used to in the home, the workplace and the coffee shop.
‘Providing internet access on a vehicle which is flying at 10,000 metres at 300kmh is inevitably going to be challenging, with the connectivity between the aircraft and the internet being the most capital intensive part of the solution,’ says Marcio Avillez, vice president of network product at iPass. ‘Airlines have also got to consider both the weight of the new equipment and the increased power consumption and recognise the ways in which they can alleviate these, for example with smaller antennae.’
‘Clearly, accessing Wi-Fi on an aircraft is considerably different to accessing the internet via Wi-Fi in a coffee shop or an airport lounge,’ adds Avillez. ‘As a result, in-flight providers typically have to invest more capital to serve the same Wi-Fi use, which explains why in-flight internet prices seem expensive in comparison to terrestrial Wi-Fi.’
One company that offers just that is Aircell in the US. The company provides services to airlines such as Continental, Delta, American Airlines, Virgin America, Air Canada and others. The company claims that over 65% of business travellers and one third of all leisure travellers in the United States carry laptops onboard when they fly. In addition, 30% carry Wi-Fi enabled phones and PDAs. The company provides services to airlines and users via its Gogo in-flight internet service (see panel).
In-flight communications face three main challenges; security, the pay-per-use business model and device battery life. Most airlines address security by using a log-on process to ensure that the person requesting access to the service is physically on the aircraft. The drawback is that it adds a further layer to an already unwieldy sign-up process.
The cumbersome nature of that process has its roots in the pay-per-use commercial model that is typically available. Although some airlines offer alternatives, the pay-per-use model is preferred by users. However, the sign-on process with most providers takes several minutes and requires a credit card.
Device battery life also limits the potential value of a session to users. Most users are limited to 2-3 hours if they are on a PC with a good battery. Some airlines have installed AC plugs in certain seating areas to address this problem, while using smartphones can also prolong the time people can stay connected while flying. However, adding power points has an impact on a plane’s power consumption and many older aircraft are simply not designed to supply individual power to every seat.
Two methods of communicating from the plane are used. One is via satellite, the other is by accessing the terrestrial cellular network. Satellite is challenged by its expense, which limits such an offer’s attractiveness to users, while cellular communications need to overcome barriers to reliable connections as the plane speeds overhead.
‘In terms of backhaul technology,
most solutions either use a terrestrial cellular 3G or 4G network or a satellite-based network to enable connectivity up in the air,’ says Avillez. ‘A terrestrial network works in countries such as the US, where fewer carriers are required and roaming fees are typically avoided. In Europe on the other hand, providers seem to prefer the satellite network due to a smaller geographic expanse of countries as well as the increased number of carriers that would need to participate in a solution.’
The market for such services is relatively new so consistent experiences are rare. ‘The reality is that it is difficult to generalise the in-flight experience to that of the on the ground experience,’ says Avillez.
‘On one end of the spectrum, you will find operators who manage their networks very well and the performance on these networks will typically exceed that of a 3G network today. However, there are also operators that have ‘free’, ‘quasi-free’ or ad-supported models and these networks don’t always - although some do - perform as well. Our experience with in-flight internet is equivalent to the performance of the underlying 3G data network in the US. I personally experienced 300k-400k up and down speeds which was quite adequate for the business applications I was using.’
For Joe Epstein, senior director of technology at Meru Networks, the aim is about providing a seamless experience; ‘Airlines today need to extend such seamless mobility and reliable coverage from the airport to the airplane as travellers rely on wireless services, such as watching live TV in the air,’ he says. ‘Fourth-generation wireless architectures are best suited for this environment to avoid network contention and deliver a reliable connection to the passenger.’
The investment required to enable passengers can also be used to the benefit of airline operators. However, this remains an early stage market. ‘We’re aware of several applications where the flight crew can use the internet on the plane to update schedules and file reports,’ says Avillez. ‘Many of the airlines are looking at using Wi-Fi as a means of distributing entertainment content in the future. Where passengers have a Wi-Fi enabled device, it may make sense to distribute movies on demand direct to their personal smartphone or laptop.’
Both feet on the ground
On land, wireless communications in the airline sector are far more developed and deployed in support of airport operations, the airlines and the travelling public. ‘Airport communications are generally managed by the local airport authority – they make the call on what will be deployed within an airport, and will include input from their customers - the airlines - when evaluating solutions,’ says John Spindler, vice president of product management at ADC.
‘Airlines generally do not act autonomously, as most communications standards are set by the local airport, and communications systems are provided for the entire venue, including passenger terminals, baggage areas and maintenance areas.’
The airport authority holds the key and jealously guards its wireless real estate. ‘In many cases, the airport operates the entire network,’ confirms Joe Epstein, senior director of technology at Meru Networks.
‘Often, they will outsource the management of the travellers’ network to a wireless hotspot provider, who uses the airport’s network but either offers advertisements for a free service or collects the credit card numbers to charge users for the network access. Concessionaires are offered their own virtual network on the same physical wireless network and are charged directly by the airport. Airlines that wish to use the airport-provided service fall into the same category.
'Sometimes, airlines will also install their own wireless network alongside the one provided by the airport, usually at hubs where they have a legacy system and are not at a point where they could transition from that to the one the airport provides. In those cases, the airport and the airline work together to ensure that they can carve up the spectrum without interfering with each other.’
‘Overall, settling on the Wi-Fi standard - but only with the right choice of the generation, for example 4G vs 2G or 3G, of the underlying Wi-Fi network technology - makes it possible to mix-and-match retail devices such as wireless cash registers with baggage handling and operations devices,’ adds Epstein. ‘Ruggedised warehouse applications that operate in the bowels of the airport rather than in stand alone buildings must be addressed while providing high quality service to the general travelling public.'