Mesh Networking in Low Power Location Systems (Swarm) SONALI DEO KTH ROYAL INSTITUTE OF TECHNOLOGY INFORMATION AND COMMUNICATION TECHNOLOGY KUNGLIGA TEKNISKA HÖGSKOLAN Royal Institute of Technology Mesh networking in low power location systems (swarm) Master Thesis Last revised: 2016-08-24 Sonali Deo Email: [email protected] Examiner Professor Mark T. Smith (KTH) Supervisors Johnny Öberg (KTH) Andreas Lagemann (nanotron Technologies) Acknowledgements This thesis is dedicated to my parents and was accomplished with the help from a lot of people to whom I wish to express my sincere thanks. I thank nanotron Technologies for giving me the opportunity to work on this topic which interested me the most from all the others that I came across. I am thankful to my supervisor at the company, Andreas Lagemann, for his enthusiasm in discussing and helping me develop new concepts for the implementation and encouraging me all the way. I thank the CTO, Rainer Hach, for introducing the Layer 2 routing protocol as a candidate in the first place and opening the possibilities for enhancement that enabled me to innovate. I am very grateful to Christian Bock, for helping me understand swarm, debugging my mistakes and for his insights in the whole implementation. At KTH, I am highly indebted to Mark Smith for guiding me in making several decisions about the project and concepts. I also thank Mark Smith and Johnny Öberg for going through my long drafts and explanations and giving valuable suggestions that helped get this thesis to where it is now. This work has given me a deeper insight to lot of things, such as, mesh networking, routing protocols, radio communication, synchronization schemes, embedded C programming and most of all, testing, which is fairly new to me. It will be very useful for my continuation of work and study. I hereby thank David, my parents and all the friends who have always given me kind help and support. I Abstract Today, Internet of Things (IoT) is the driving force in making operations and processes smart. Indoor localization is such an application of IoT that has proven the potential of location awareness in countless scenarios, from mines to industries to even people. nanotron Technologies GmbH, based in Berlin, is one of the pioneers in low power location systems. nanotron's embedded location platform delivers location-awareness for safety and productivity solutions across industrial and consumer markets. The platform consists of chips, modules and software that enable precise real-time positioning and concurrent wireless communication. The ubiquitous proliferation of interoperable platforms is creating the location- aware Internet of Things. One of their product families is swarm. A swarm is a group of independent radios or nodes which facilitates the nodes to communicate with their immediate neighboring nodes to get each other’s positions. This position information is collected by one of the nodes (called gateway) and delivered to the host controller. However, the nodes need to be in range to communicate. The company wants to improve the range of communication and for that purpose; I am implementing a routing protocol with some additional changes for swarm, to allow out-of-range nodes to communicate via intermediate neighbors. This is called mesh networking which would result in so-called ‘mesh’ of nodes and would increase the range of swarm operation that could be beneficial in achieving uniform connectivity throughout large spaces without needing excessive number of gateways. This is of high importance because a node acting as gateway should be ‘awake’ all the time so that it can collect data efficiently, while the other nodes can be on power saving mode. Mesh networking will allow data collection even with fewer such gateways thereby being energy efficient while facilitating larger range of communication. This was made possible by adding the feature of allowing nodes to store messages for their neighbors in case they are asleep and wake up for the neighbors to transmit data. It is done using a schedule that is built and updated in addition to the routing protocol. The purpose of this thesis is to justify the implemented mesh routing protocol for swarm among all the other routing protocols available. It also focuses on the modifications and improvements that were devised to make the protocol tailored for how swarm works and to support Message Queuing Telemetry Transport (MQTT) on top of it, at a later stage. MQTT is a lightweight messaging protocol that provides resource-constrained network clients with a simple way to distribute information. It uses a publish/subscribe communication pattern and is used for machine-to-machine (M2M) communication and plays an important role in the Internet of Things. The implemented routing protocol also takes into consideration, the sleeping nodes, route maintenance through advertisements, hierarchical nature of mesh to make data collection more efficient, message formats keeping in mind the memory shortage, etc. The document gives a thorough overview of concepts, design implementation, improvements and tests to prove the importance of mesh networking in existing swarm. Keywords: WSN, routing, nanotron technologies, indoor positioning, swarm, mesh networking II Table of contents Acronyms and abbreviations .....................................................................................................................1 Chapter 1: Introduction ..............................................................................................................................4 1.1. Background ..................................................................................................................................4 1.2. swarm bee LE ................................................................................................................................5 1.3. Overview – Comparison of routing protocols ........................................................................6 1.4. Goals ............................................................................................................................................12 1.5. Organization ................................................................................................................................12 Chapter 2: Concepts ..................................................................................................................................13 2.1. Principle of swarm .......................................................................................................................13 2.2. swarm API ....................................................................................................................................16 Chapter 3: Design ......................................................................................................................................20 3.1. Proposed routing protocol ........................................................................................................20 3.2. Additional custom features .......................................................................................................32 3.3. Frame formats used ....................................................................................................................35 Chapter 4: Implementation ......................................................................................................................40 Chapter 5: Validation and testing ...........................................................................................................51 5.1. Tools used ....................................................................................................................................51 5.2. Analysis of transmission and reception ..................................................................................57 Chapter 6: Results and Evaluation ..........................................................................................................60 6.1. Data analysis and evaluation ....................................................................................................60 Chapter 7: Conclusions .............................................................................................................................72 7.1. Conclusion ...................................................................................................................................72 7.2. Future work .................................................................................................................................73 References ...................................................................................................................................................75 Appendices .................................................................................................................................................76 Appendix 1: Common swarm commands used .............................................................................76 Appendix 2: Frame formats .............................................................................................................80 Appendix 3: List of figures and tables ............................................................................................82 III Acronyms and abbreviations ACK Acknowledgement ADV Advertise AIR Wireless medium AODV Ad hoc On demand Distance Vector API Application Programming Interface APP Application layer BSN Beacon sequence number CDMA Code Division