Mobile Phone Tools

In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including Sprint PCS, Cingular Wireless, Verizon and T-Mobile use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs.

The GSM Association is an international organization founded in 1987, dedicated to providing, developing, and overseeing the worldwide wireless standard of GSM. CDMA, a proprietary standard designed by Qualcomm in the United States, has been the dominant network standard for North America and parts of Asia. However, GSM networks continue to make inroads in the United States, as CDMA networks make progress in other parts of the world. There are camps on both sides that firmly believe either GSM or CDMA architecture is superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful.

Coverage: The most important factor is getting service in the areas you will be using your phone. Upon viewing competitors' coverage maps you may discover that only GSM or CDMA carriers offer cellular service in your area. If so, there is no decision to be made, but most people will find that they do have a choice.

I want to develop a java application that can send MMS from PC to handphone. I found out that I can use MMS Java Library from Nokia to compose the MMS and send it using WAP stack. Now, I am using jWAP as the WAP stack. But I am a bit confused about the headers and the sending part.

I understand that the step to send mms is:

PC -> connect to GPRS -> connect to WAP gateway -> connect to MMSC, post the file and the rest we leave it for the MMSC to send the MMS to the handphone.

I am able to connect to GPRS and WAP gateway but I can not connect to MMSC eventhough I use the URL given by my local provider.
Can somebody help me in explaining wat is the header and how to send the MMS file? Wat is the MMS file extension? .mms or .smil?
can provide me with some kind of url or sample code? Thank you in advance.