As competition expands among airlines to offer passengers the latest in-flight entertainment options, intercontinental routes have been slow to add Internet service.

Because in-flight Internet relies on transmitting signals to the ground, intercontinental flights have yet to find a reliably cost-effective means of providing passengers with Wi-Fi service while over water. The main drawbacks are cost and the added weight of the equipment neeaided for satellite transmission.

Several airlines have plans to roll out transcontinental Internet service this year.

This month, Qantas is partnering with a company called OnAir to test satellite-based Internet service aboard flights from Australia to Los Angeles.

Japan's JAL intends to roll out Internet service to passengers flying from Japan to Europe and North America this summer. United Airlines is reportedly exploring Internet service on international flights. Emirates Airlines says it plans to test satellite based internet service on its A380 double-deck, wide-body jets.

Meanwhile, nearly all U.S. airlines have announced plans to install Internet service and added amenities on domestic aircraft in recent years.

In-flight Internet service provider GoGo announced Wednesday that it has reached a deal to expand service aboard US Airways fleet of Airbus A319, A320 and Embraer 190 aircrafts.

Delta Airlines recently announced it was partnering with Amazon to provide passengers with free access to shop the online retail giant's website onboard all of Delta and Delta Connection flights with in-flight Wi-Fi service.