Applying Ulysses to Bluetooth Alvise Bonivento Mentor: Marco Sgroi

Outline Motivations The Ulysses methodology Introduction to Bluetooth Bluetooth from an Ulysses perspective Extensions to Ulysses Conclusions and future works

MOTIVATIONS: PROTOCOL DESIGN METHODOLOGY Traditional design approaches are informal Early partition of the system behavior increases number of errors Need of a formal approach enabling IP reuse Scenario based specifications

Ulysses Design Flow Scenario Specification (Message Sequence Charts + relations) Synthesis of Petri Nets (MSC Covering) Scenarios composition Mapping and Optimization

Bluetooth Applications ACLSCO Baseband LMP HCI L2CAP RFCOMM OBEXWAPSDP Services: Asynchronous Connection-Less (ACL) and Synchronous Connection Oriented Service Discovery Protocol (SDP): table of services L2CAP: Adaptation layer, segmentation and reassembly Host Control Interface: Interface HW and SW Link Manager Protocol (LMP): a CPU implemented on HCI Baseband: LLC + PHY Radio:2.4 GHz (IMS), FHSS, 79 Channels, of 1 MHz each Piconets with a master and a maximum of 7 active slaves

Bluetooth: examples Authentication

Bluetooth: example Encryption and connection set-up

ALL THIS TRANSITIONS CAN BE CONSIDERED PATTERNS Bluetooth: example HIGH LEVEL SCENARIO COMPOSITION !!!!! DESCRIBE THIS TRANSITIONS WITH OTHER PNs

Starting from Ulysses Authomatic synthesis of communication protocols not effective: layer by layer refinement very hard Next generation protocols: 4G (beyond 3G) ? New key parameters OSI type protocol stack may not be the most appropriate solution Need to provide an authomatic synthesis tool able to deploy “super networks” A new methodology with higher level of abstraction

Platform based design Specifications + constraints (power, area, latency, QOS...) Translation into a labeled PN model Optimized labeled PNs Library of architectures (SW/HW) + performances Bottom-up abstraction of resources Mapping Labeled MSN Simulations and synthesis tool: Metropolis At this level they can talk !!!

Conclusions Ulysses: a new approach Scenario based PNs as MoC pattern Case study: Bluetooth: MSN description, PN translation, Metropolis. Platform based design for communication protocols Future work: A LOT !!! More patterns and examples Extend the model in order to capture more aspetcs (i.e. power, area, latency... Environment ?) Implement authomatic PNs generation from MSNs

Covering Algorithm tj=t0 Repeat BeginCoverM Repeat Select ei s.t. Ei is a cut if ei is receive add Channel SelectPattern LabelPattern ComposePattern i++ Until all e in Mj are covered if all e in Mj are covered mark tj EndCoverM Select next transition tj with all predecessors covered or a marked predecessor place Until all transitions are covered For every choice add a synchronizer Add initial marking Tokens