Overview
International roaming is a critical feature for global travelers today. The CDG International Roaming team leads the effort in the CDMA community to provide our subscribers the ever-increasing ability to enjoy the benefits of CDMA service globally. Our team members have developedwith implementation guidelines for internetworking, billing, and testing to enable a service provider to quickly deploy international roaming service for their customers. Today, the team focuses on ensuring that roaming subscribers will enjoy their CDMA2000 data services wherever they travel. We are also spearheading the effort to provide inter-standard (CDMA/GSM) roaming capability to further expand service.

Int'l Roaming Using CDMA (Courtesy of Cellular Networking Perspectives)
International roaming allows users of CDMA wireless phones to travel to a foreign country and enjoy many of the same services there that they can at home.

While there are still many challenges to obtain fully seamless international roaming across various 2G and 3G technologies and frequency bands, CDMA subscribers can enjoy some of the finest international roaming available. And, it will only get better in the future.

What is Roaming? (Courtesy of Cellular Networking Perspectives)
Roaming is the ability of a system to provide the same services to customers (‘roamers’) from other systems, even from other countries. This involves the resolution of a number of business and technical challenges. Some of the major services that can be provided are:

• The ability to make a call (‘Mobile Origination’). While this sounds simple, this fundamental service requires a wireless system to verify that the customer's subscription is valid, that the phone is not stolen, that it is not illegally emulating another phone, and to ensure that the type of call being made is not restricted.
• The ability to receive a call (‘Mobile Termination’ or ‘Call Delivery’). This is technically much more complex, and requires the roamer's phone to first register in the system in which it wishes to receive calls. This is done automatically, and causes an exchange of information over the SS7/ANSI-41 network to the home system. When a call comes in to the home system it already knows where the mobile is, and can route a call to it.
• Inter-system handoff. This allows a mobile call to continue uninterrupted when the mobile crosses the boundary between two cellular systems.
• Short Message Service. When an SMS message comes in to the home system it will be forwarded to the mobile, wherever it is.
• Calling Name/Number Presentation. When receiving a call, the number of the caller or even their name will be displayed on their handset.
• International dialing. Some phones provide a “+” key or equivalent menu option that makes it easy to place an international call without knowing the local access number.