In this paper, a new wireless medium access control protocol, called Mini-Packets Reservation Multiple Access (MPRMA), is proposed for the microcellular wireless environments to support voice and data traffic. Instead of using information packets to contend for reservation, the protocol uses smaller reservation packets for contention. Thus, regular slots can be further divided into smaller slots for sending reservation packets. Furthermore, in order to facilitate subsequent packet transmission, a continuation flag is used in each information packet for requesting further reservation. Comparing to the Packet Reservation Multiple Access (PRMA), it is shown by simulation that MPRMA can support more voice and data users, respectively, in a single traffic type environment. And more importantly, MPRMA is also a better alternative to PRMA for supporting voice-data integration. In order to counter adverse channel conditions, a strategy is also proposed. In addition, MPRMA requires no deadline scheduling at the base stations and minimizes overhead bandwidth on the downlink for sending acknowledgment messages.

Media synchronization and freedom from starvation at destination devices are the two most important problems in a multimedia communication system. In order to solve these problems at the same time, this paper presents a protocol combining the scheduling scheme and the buffering scheme with underflow threshold (SBUF). In this protocol, by controlling the buffer sizes and modifying transmission schedule of the synchronizer synchronization can be achieved without synchronizing clocks during a connection. In this paper the algorithm of the protocol is described. The setting of the system parameters and network QOS to support the proposed protocol are also given in this paper. A simulation is performed for comparison of four synchronization schemes: scheduling schemes (with and without clock synchronization), marker scheme, and the proposed SBUF protocol. The results confirm that the proposed protocol guarantees satisfaction of QOS requirements and also performs better than the other schemes in terms of media synchronization and freedom from starvation at destination devices.

The media streams of a multimedia communication application may traverse through different communication channels. Because of the network delay and jitter, data in these streams sent at the same time may not arrive at a destination simultaneously. In this paper a multimedia synchronization protocol that resynchronizes the media streams is proposed. The protocol inserts extra control cells into the media streams, and aligns the cells at the receiver site. Three synchronization policies, namely, the Drop-Old, the Transmit-Old and the Delayed-Transmit, are introduced to align the control cells. To satisfy the Quality of Service (QOS) specified by an application, the protocol must negotiate an appropriate QOS with the underlying ATM network. For each of the three synchronization policies, the relationship between the specified QOS and the negotiated QOS is derived.>

In this paper a method is proposed to produce test paths that check both data flow and control flow for a protocol specified in the extended finite state machine (EFSM) model. The method first identifies a set of paths from a given specification to cover a data flow selection criterion, then it appends state check sequences to some transitions in this set of paths for checking control flow. The criterion that our method employs for selecting these transitions is called effective domain for testing. Effective domain for testing is used to evaluate how effective a transition can be tested in a given path in terms of the range of values that the variables in this transition can have. Since each transition can appear in several paths, our method is to append state check sequences to its occurrences that have distinct effective domains. In addition, our method will compute the path domain for each path and make some inexecutable paths executable.>