Teracom (Sweden)

The MEMO (Multimedia Environment for Mobiles) system has been developed in an ACTS project (AC064) and is built upon Digital Audio Broadcasting (DAB) and GSM networks. It is a hybrid network offering both interactive broadcast services and personal services with a much higher downlink bandwidth than GSM alone. A number of interesting problems have been solved resulting in an object-oriented service model for service providers and an extension of the socket API paradigm to facilitate access to broadcast services by mobile terminals. In addition, a cellular DAB network is proposed with mobility management based on Mobile IP, and TCP extensions to optimise the transport over the combined DAB downlink and GSM uplink. The MEMO specifications are open and are managed by the MEMO Forum, launched in March 1999.

The objective of the MEMO project is to design, integrate and operate applications which utilise interactive DAB services, i.e. combining the existing GSM mobile telecommunications network and the Digital Audio Broadcasting system. A first trial with this platform for mobile multimedia services was performed to demonstrate the results achieved after one year of work and cooperation of the European partners involved. The MEMO architecture comprises DAB transmitter equipment and PC-based terminals. During the specification of the first generation prototype and the software/hardware development the following results were achieved: Infrastructure and transmitter equipment (Specification and implementation of a protocol for information interchange between contents providers and the DAB network; design and implementation of the multi-network server (MNS) with an interface to the DAB-network-server (DNS) to feed the DAB transmitter; set-up of a DAB test transmitter at CCETT, Rennes; specification of a protocol for broadcasting Multimedia data on DAB) and Terminal (development of prototype DAB receivers with a data interface and PC plug-in card, notebook PCs and interface equipment to connect the PCs to the DAB receiver for data transfer at data rates up to 256 kbit/s; implementation of the GSM interaction channel between the mobile terminal and the MNS; definition and partial implementation of Application Programming Interfaces (APIs); development of terminal software for the network/system/application service layer and adaptation of publishing and construction industry applications to demonstrate mobile, interactive services). For the trial, the transmission chain from GSM request to DAB download was successfully completed and operated, including the connection between information provider and network operator. Three interactive applications were implemented and tested — a specialised software for the building construction industry, a system to download issues of a newspaper and a general software to transmit data objects — representing the contrary edges of services MEMO is targeting. Thus, the approach of interactive mobile services at high data rates was presented for the first time to potential customers and users providing valuable results.