Peter Sjödin

The DTM Gigabit Network

DTM is a set of protocols for high-speed networks, based on bandwidth reservation and with support for dynamic reallocation of bandwidth. It is designed for real-time multimedia applications and for high-speed computer communication. DTM uses a novel medium-access technique and provides a multicast, fast circuit-switched service. Several DTM networks can be connected into one large network. A prototype implementation and testbed is being constructed.

The Complete Axiomatization of Cs-congruence

The coupled simulation equivalence is slightly larger than observation equivalence. Where observation equivalence is based on weak bisimulations, coupled simulation equivalence is based on pairs of simulations which coincide at stable states. We establish the corresponding congruence and provide a complete axiomatization by adding a new Τ-law, Τ.(Τ. P + Q) = Τ. P + Q, to the axiomatization of observation congruence. We further indicate how the definition of the equivalence can be extended to divergent transition systems.

Designing a multiway synchronization protocol

A multiway synchronization protocol makes it possible for several processes to synchronize in an environment where communication is asynchronous. We present the design of such a protocol. The design methodology is based on formulating the behaviour of the entities as transition systems. This admits a correctness proof: we show that the protocol is correct relatively an ideal non-distributed algorithm, in the sense that the protocol and the ideal algorithm cannot be separated by any amount of testing. The proof method is based on cs-equivalence.

Resource reservation in DTM

DTM is an optical network with bandwidth reservation and support for dynamic reallocation of bandwidth. DTM is designed for real-time multimedia applications and for high-speed computer communication. DTM provides a service with real-time guarantees: it allows reservation of bandwidth, and has constant delay between two nodes. DTM uses a novel medium-access technique and provides a multicast channel service. The paper describes how resources are reserved in DTM, and describes a DTM prototype implementation to demonstrate that the protocols can be implemented efficiently.<<ETX>>