aming is an extra challenge. Let us take a look at an MMS call from Singapore to Sweden. The home operator is Swedish. Peter's operator in Sweden will charge him for a person-to-person MMS. The operator in Singapore wants to get paid for letting Peter send a MMS via their network. So there will be need for a roaming settlement between the Singaporean operator and Peter's operator in Sweden. Somebody is transporting the MMS from Singapore, and wants to get paid for this. Meaning interconnect settlement for the MMS transiting. And once again this might sound simple. But it is not. Operators must have this in place in order to make MMS take off and be able to capture the revenues. For example: What is the right MMS price level? The relationships for buying and selling content, interconnection and roaming services keep increasing in complexity and values. It is becoming increasingly important for operators to make sure that they can charge and get paid for everything they have delivered to their partners. Another requirement is Understanding Changing Telecommunications - Building a Successful Telecom Business Home PLMN: Sweden Home SN backbone network IVITY MMS roaming settlement Bac bone MMS interconnect Net vork settlement Backbone MMS-C Network Visiting PLMN: Visiting SN Singapore Charge user for MMS Figure 15.20 MMS roaming charging to be able to verify and make sure that the claims from their partners are correct, in order to avoid being overcharged. 15.14 POSSIBLE INTERWORKING UMTS-WLAN This type of interworking might become very common in the future, including roaming. 15.14.1 REQUIREMENTS A cooperation of UMTS-WLAN combines the wide-area benefit of 3G with its unlim- ited roaming and mobility with the additional throughput and capacity by WLAN in hot spots. WLAN surf points are increasing quickly all over the world with a predicted num- ber of 120 000 in 2007 (Source: Gartner-Dataquest). WLAN users can be part of the 3G-operator subscriber base and UMTS-WLAN operators are enabled to offer further 3G packet se