You couldn't help but stare at the e-mail inbox. Were these messages for real? It used to be just the corporate jet set and desperate suits who were willing to shell out the US $10 a minute to hook their laptops up to seatback phones in order to send e-mail. Is inflight e-mail finally becoming a reality for the masses?
Indeed. As the plane-to-plane exchange of e-mail—a clever marketing gimmick staged by Tenzing Communications Inc., Seattle, Wash.—showed, commercial airlines are now looking to deploy a slew of new inflight technologies for business as well as entertainment. And competition is fierce: in recent months, Tenzing has signed up seven airlines for its narrowband Internet and e-mail service, and airplane manufacturer Airbus, headquartered in Toulouse, France, has bought a 30 percent stake in the company. Meanwhile, Connexion by Boeing (a Boeing Co. subsidiary based in Irvine, Calif.) has lined up American, Delta, and United airlines for its broadband inflight service.
fly01.jpg At the annual Inflight Passenger Entertainment and Communications Conference in London last April, some 400 attendees got a taste of what's coming from the likes of Tenzing, Boeing, Thales Avionics, General Dynamics, and Rockwell Collins. E-mail is on the way, as well as Web surfing and on-line shopping, cellular telephone and wireless modem use, and live radio and television. The inflight entertainment market is huge and growing: some $2.4 billion at present, with projected growth to $7.4 billion by 2007, according to research firm Frost & Sullivan, based in San Jose, Calif. The goal is to keep frequent fliers connected to their cell phones, Palm Pilots, and the Internet long after the seatbelts have been fastened, tray tables stowed, and the plane has climbed to 40 000 feet.
It's enough to make even the weariest road warrior forget about the airplane food and flight delays—well, almost. No technology is that advanced.
Coffee, tea, or e-mail?
The flurry of airborne data services comes as airlines scramble to win over business travelers, who now make up roughly half of all fliers—about 40 million annually worldwide—and the lion's share of the airline industry's profits, and tend to expect better service.
"It's seldom you can take eight hours out of a business person's life and not have them miss something," said Terry Wiseman, publisher of Airfax, a newsletter covering the inflight entertainment industry. "Airlines are now paying the equivalent of a jet engine" to equip a plane with inflight systems.
"There are some killer applications coming to the aircraft, the main one being e-mail," Wiseman added. Delivering e-mail and Internet access to passengers can be done in two ways: narrowband and broadband. High-speed networks on board the aircraft, meanwhile, distribute data, as well as power, throughout the cabin.
Narrowband Think slowing down to go forward. For the next year or two, broadband connections will remain too expensive, and so some carriers are opting for narrowband connections, a less expensive, but more limited approach. Narrowband aggregates, compresses, and transmits e-mail at very low speeds to the Internet. Similarly, Web surfing is limited to sites that have been cached in on-board servers before takeoff. For those accustomed to instant messaging and T1 connections at the office, narrowband can seem painfully slow or limited. Cost is its main advantage: narrowband installation ranges from $30 000 to $50 000 per aircraft and takes about five hours, compared to broadband's $4 million and two weeks.
To send and receive e-mail, a passenger plugs her laptop into the seat-back phone, which dials an on-board server. The laptop transfers e-mail at 56 kb/s to the server, which stores and compresses bundles of messages before sending them at 2.4- 9.6 kb/s at UHF, 1-2 GHz (L band), or 18-27 GHz (K band), depending on the aircraft. (The lack of real estate in the 1-40-GHz radio frequency spectrum preferred by inflight service providers means that separate frequencies are often allocated for communications from the ground to the aircraft, aircraft to satellite, and so on; see figure.)
The e-mail bundles are sent every 15 minutes to ground servers, which then send the data to the Internet or to corporate accounts. The ground control system also pulls the user's e-mail from the Internet, then bundles, compresses, and transmits it to the plane at the same speeds. Signals to and from the ground travel by way of the North American telephone system during flights over North America and by satellite over the ocean and elsewhere. This setup also lets passengers on the same flight bypass the Internet and instead communicate with each other through the on-board intranet.