Late Call Forwarding, Optimal Routing, and Roaming Trombone
The increasing popularity of cellular phones has greatly changed the telecommunication industry of this decade. Cellular phone users, for example, make use not only of the cellular networks, but they also make use of the traditional telephone networks to route or forward calls. Cellular networks have also evolved into two basic types, namely, the American National Standards Institute-41 or ANSI-41 and the Global Systems for Mobile communications (GSM).
A deeper look into the kind of message format used by these two different kinds of cellular networks would readily reveal that each of these two cellular networks uses different or non-compatible message formats. Hence, if one is using one of the cellular network formats and is calling another cellular network with different format, the message format has to be converted into the other type of format for the message format to be understood and completed. Roaming, in this sense, requires a conversion of message format from one format to another message format. The conversion from one message format to another often requires the use of Interworking/interoperability Unit. This unit generally interconnects the center that is calling and the one that is being called. This IWU passes back and forth signaling messages while at the same time converts the message format from one form to another. Although this process may be a bit intricate to the mind of the ordinary subscribers, this process is definitely valuable and regularly takes place whenever there is a discrepancy in the message formats between the called mobile services and the calling mobile services.
What is Optimal Routing Design?
Optimal routing is a feature of a network that generally enables calls—that are directed to a particular mobile subscriber—to be directly routed to the actual location of the mobile subscriber or to his/her “forwarded-to” destination. The benefits of optimal routing are very obvious to those who are cognizant of the intricacies of the roaming system. First, it benefits the operators and readily enable them to route all roaming calls in the most effective and efficient way. This leads to increase efficiency and is cost-effective for the operators. If the operator, for example passes the cost savings derivable from the use of this feature to their subscribers, subscribers will surely appreciate it and thus become more loyal to their mobile service operator. On the other hand, if it is not passed on to the subscribers and is retained by the operator, then the operator readily increases its profits. Thus, in either of the two ways, the operator benefits from the utilization of the optimal routing feature.
Understanding International Voice Mail Tromboning
One basic problem that roamers usually experience when using their roaming plan is "roaming trombone." Tromboning occurs when a subscriber calls someone who can't quickly answer the phone because of his unavailability. This call is then routed to the visited network and back to the local network, and eventually to the voicemail. A significant cost is often concomitant with this routing and rerouting process, and this cost add up to the bills of the subscribers. This international voice mail tromboning can be readily resolved by introducing a plug-in roaming gateway that can readily help avoid the unwanted and expensive international trunk connections











