Towards an implementation of the IEEE 802.15.4 time critical MAC extensions over a real-time OS
Ref: CISTER-TR-181130 Publication Date: 14, Nov, 2018
Towards an implementation of the IEEE 802.15.4 time critical MAC extensions over a real-time OS
Ref: CISTER-TR-181130 Publication Date: 14, Nov, 2018Abstract:
Growing at a fast pace, the adoption of embedded computing systems, capable
of monitoring and controlling the physical environment around them, is spreading
across different environments, from our houses to the industrial setting. This
latest trend, induced by recent advancements in the information and communication
fields, craves for the new Wireless Sensor Network (WSN) concept, which
aims to enable an infrastructure that interconnects the set of widespread “intelligent”
devices, capable of wireless communications, constituting a network of
sensor nodes.
On an Industrial context, the new Cyber-Physical Systems (CPS), prompted
by the Industry 4.0 revolution, aim to correlate the present automated systems
to the new information technologies, such as cloud and cognitive computing,
to compose a group of collaborative computing systems that enact the “smart
factory”. This new targeted model however, relies on certain time assurances and
other QoS (Quality of Service) properties such as scalability, energy efficiency
and robustness, which WSN technologies intent to grant. Although a tender
paradigm, propositions such as the IEEE std. 802.15.4 protocol ambition to
enable the WSN infrastructure and satisfy the QoS requirements.
The IEEE std. 802.15.4 protocol provides several MAC (Medium Access
control) behaviours to frame the communications stack, each aiming to meet
the set of requirements of distinct applications. For deterministic latency, high
reliability and scalability QoS requirements, IEEE 802.15.4 standard provides the
DSME(Deterministic Synchronous Multichannel Extension) MAC behaviour.
Parallel to the phenomenon of the WSN technologies, real-time operating
systems (RTOS) are emerging among the IoT(Internet of Things) community to
help tackle QoS specifications for determinism and time-critical constraints.
The use of a real-time OS in conjunction with a time reliable protocol such
as DSME is the key to enable a truly deterministic and time critical WSN.
However, besides these settings, QoS at the computing platform must be
guaranteed as well if these network infrastructures are to become a reality. Computations
must be performed in a predictable way, as to support the QoS demands
in terms of latency these networks present. Hence, in this Thesis we propose to
rely on the FreeRTOS for a real-time operating system and a well known WSN
platform, such as the TelosB to implement the DSME time critical MAC behaviour.
To achieve this defined goal, this Thesis presents a port of FreeRTOS to
the TelosB platform, wich includes an IEEE 802.15.4 compliant radio, as well as a
preliminary study of the future implementation strategy of the network protocol.
Hereby, this Thesis concludes with a successful implementation of the RTOS,
FreeRTOS, for the TelosB platform, along with the necessary groundwork and
time requirements support for the DSME extension. Additionally the Thesis
provides a suggested model for the protocol stack to fit the FreeRTOS task system.
Document:
BEng Thesis, Instituto Superior de Engenharia do Porto.
Porto.
Notes: Orientação científica: Ricardo Severino Co-Orientação: Harrison Kurunathan
Record Date: 22, Nov, 2018