SMS (short message service) and MMS (multimedia message service) are two of the hottest services in wireless communications today, offering customers exciting ways to communicate by sending text and multimedia messages. This comprehensive book offers wireless engineers and managers practical guidance in the planning and implementation of SMS and MMS services with interworking (the ability to successfully send a message when the origin and destination cellular phones do not use the same wireless operator). The book offers professionals various solutions to the common problem of number portability (a situation when a cellular phone has been "portedout" to another operator while keeping the same number) and provides methods for blocking spam from inbound SMS. Including numerous solved examples, this authoritative reference helps practitioners master of the key concepts they need to understand for their work in the field.