Java Reference
In-Depth Information
CHAPTER 11
■ ■ ■
Wireless Messaging API
U
sing the Internet on your cell phone is fun, but it can be quite costly. Connection time is
billed per minute or per packet, and this can add up fast to a fat bill. In most cases, a lower cost
alternative is readily available. Called Short Message Service (SMS), it is often offered by national
carriers as text messaging.
The Wireless Messaging API, or WMA, is an optional API that enables MIDP applications
to leverage the utility of SMS. In addition, the API can be used for receiving and processing Cell
Broadcast Service (CBS) messages. WMA 2.0, recently finalized, adds the support for Multimedia
Message Service (MMS) messages. It becomes easy for MIDP applications to send and receive
images, video, and other multimedia content.
Ubiquitous SMS
Short Message Service, or SMS, is one of the most widely available and popular services for
cell phone users. Often sold as text messaging service, it is the ability to send short messages
between phone users.
SMS has its origin back in the day when cellular phones were expensive and operated over
mostly analog-based technology. Even though the voice portion of a phone call is circuit
switched over an analog network, the control network for the call is digital, and it has spare
capacity to carry a small text message.
Since those early days, SMS has undergone some major technical changes under the hood.
The user experience, however, remains the same.
The ubiquitous nature of SMS means that it is supported worldwide on cellular networks
of (almost) any technology, including but not limited to TDMA, CDMA, WCDMA, GSM, GPRS,
CDMA2000-1X, CDMA2000-MX, and EDGE.
SMS: The Killer App for Wireless
The ability to send short text messages (up to 160 characters in most cases) between cell phone
users inexpensively is compelling enough. The possibility to send messages directly between
J2ME applications running on cellular phones is even more exciting. Messages can now be sent
and received between phones without
•
Having Internet access from the phone (potentially additional cost service)
•
Going through an intermediary server (potentially from the carrier at additional cost)
•
Being restricted in terms of routing by the carrier's network
165
Search WWH ::
Custom Search