CS4491/02 Fog Computing The Things 1
Guiding questions • What to think about things and how are they connected? • What is the difference between IoT, WSN, M2M? 2
Physical elements: devices and networks • ‘ Thing s’: low capacity devices – (T-S) sensors – (T-A) actuators – (T-I) identifier (special sensor) • Infra structure: – (I-S) switches ( layer 2 connectivity within a network technology) – (I-G) gateways • converting between two parties • different layers of the OSI stack – networks, e.g. (wireless) LANs, PANs • (S) Storage devices – e.g. SAN or NAS, Cloud storage • (U) User devices: phones, tablets, desktops, laptops • (E) Embedded devices (containing several functions) • (F) ‘ Fog ’: high capacity devices in the vicinity of data generation • (C) ‘ Cloud s’: massive storage and execution power 3
Resource limitations • Memory : available flash (‘ program code ’) and ram • Processor : Mhz , instruction set expressive power, address width, ability to manage its power • Energy : available Joules and how they are replenished • Communication : required transceive power, bps , complexity of protocols • These are connected, mainly through energy – Ram requires power to retain state – Processor complexity and Mhz require energy – Small memory needs fewer address bits – Simpler network protocols and smaller bandwidths lead to lower power transceivers 4
RFC 7228: Terminology for Constrained- Node Networks - IETF • Three classes representing memory (hence processor) limitations • C0 : dependent on proxies for secure Internet inclusion • C1 : only low resource protocols • C2 : can run most Internet protocols • ( C9 : phone, tablet, desktop) 5
Energy limitation and communication policies 6
Some private taxonomy Flash RAM Address Processor OS Energy Operation Actively Example space (type) reachable A small several <= 8bits ~100Hz no External, or Externally activated, simple read/write not designed RFID tag, code bytes battery + for reachability ISO 18000- via multi-hop memory wakeup 6c B <= 32K Few <=16 ~1Mhz mechanical mechanically activated, just generates no; needs power switch no, or some data hundreds bits TMS430 simple proxy executive C <=32K Few <=16 ~1Mhz Contiki, battery simple, fixed external behavior, needs duty cycled, simple hundreds bits TMS430 TinyOS proxy, simple sensing needs proxy sensor mote D <=32K ~10K <=16 ~1Mhz Contiki, battery + capable of managing most constrained self-managed Crossbow bits TMS430 TinyOS recharge IP protocols, sensing, actuating, on/off behavior processing E <=256K ~32K <=32 ~1-10Mhz Contiki, complete IP endpoint behavior, limited yes Jennic mote battery + bits ARM TinyOS recharge, storage mains F ~GB ~500Mb 32 bits ~Ghz Linux battery + full fledged embedded computer system yes Rasberry PI ARM recharge, mains G phones, laptops, servers 7
Some private taxonomy Flash RAM Address Processor OS Energy Operation Actively Category space (type) reachable A small several <= 8bits ~100Hz no External, or Externally activated, simple read/write not designed C0,E0,P0 code bytes battery + for reachability via multi-hop memory wakeup B <= 32K Few <=16 ~1Mhz mechanical mechanically activated, just generates no; needs C1,E0,P0 no, or some data hundreds bits TMS430 simple proxy executive C <=32K Few <=16 ~1Mhz Contiki, battery simple, fixed external behavior, needs duty cycled, C1, E2,P1 hundreds bits TMS430 TinyOS proxy, simple sensing needs proxy D <=32K ~10K <=16 ~1Mhz Contiki, battery + capable of managing most constrained self-managed C1,E1,P1 bits TMS430 TinyOS recharge IP protocols, sensing, actuating, on/off behavior processing E <=256K ~32K <=32 ~1-10Mhz Contiki, complete IP endpoint behavior, limited yes C2,E1/9,P1/9 battery + bits ARM TinyOS recharge, storage mains F ~GB ~500Mb 32 bits ~Ghz Linux battery + full fledged embedded computer system yes C9,E9,P9 ARM recharge, mains G phones, laptops, servers 8
Example: A battery-less light switch • The switch is pressed. • The node turns on and sends a Route Request broadcast message for a known destination. – it boots an OS in the process! • Using Route Reply, it finds the route to the luminaries. • Using the discovered route, the node transmits 30mA @ 3.3V for 60ms the control signal (turn on/off) to the luminaries. Running FreeRTOS and capable of transmitting compressed IP • The luminary node acknowledges the reception packets (6LoWPAN). of the control signal. From: 6LoWP AN: IPv6 for • Battery-less Building Networks, The switch node does multiple retries to transmit MSc thesis of N.A. Abbasi, TU/e that control signal as long as the node stays on and until an ACK is received. 9
Functionality of things • ‘ Thing s’ must be capable to perform the required sensing, actuation, computation, communication – functional requirements • In addition, because they are many: – (secure) bootstrap, (secure) network association • upon (re)starting a device must load its code from a trusted source • it must join the correct network – secure communication – (secure) software update, over the network • updates are inevitable and must remain safe – … part of the life cycle 10
Concerns and management • - can it join a network? A,B,C: need trusted partner (proxy) - secure bootstrapping • A,B: very little; C: limited - can it be configured? - adapting operational parameters - e.g. sensing, communication frequency • From D onwards - can it be updated (over the air)? - new firmware, new services, new application components - can it run IP? • From E onwards; D runs - serve as IP endpoint limited protocols - can it secure itself? • A,B,C: via trusted partner or specialized protocols for single - independent node interactions; D: limited 11
Some private taxonomy Flash RAM Address Processor OS Energy Operation Actively Example space (type) reachable A small several <= 8bits ~100Hz no External, or Externally activated, simple read/write not designed RFID tag, code bytes battery + for reachability ISO 18000- via multi-hop memory wakeup 6c B <= 32K Few <=16 ~1Mhz mechanical mechanically activated, just generates no; needs power switch no, or some data hundreds bits TMS430 simple proxy executive C <=32K Few <=16 ~1Mhz Contiki, battery simple, fixed external behavior, needs duty cycled, simple hundreds bits TMS430 TinyOS proxy, simple sensing needs proxy sensor mote D <=32K ~10K <=16 ~1Mhz Contiki, battery + capable of managing most constrained self-managed Crossbow bits TMS430 TinyOS recharge IP protocols, sensing, actuating, on/off behavior processing E <=256K ~32K <=32 ~1-10Mhz Contiki, complete IP endpoint behavior, limited yes Jennic mote battery + bits ARM TinyOS recharge, storage mains F ~GB ~500Mb 32 bits ~Ghz Linux battery + full fledged embedded computer system yes Rasberry PI ARM recharge, mains G phones, laptops, servers 12
W hat’s new with IoT? • • There are many things Their numbers and far-reaching – #things / person >> 1 (50B in 2020) locations enable entirely new applications – hence, things need to talk to each – large-scale data collection other or to a database • about …..? – data-based applications – self-* properties, autonomy – manufacturers probing into the • self management, self healing, … deployed systems – scalability, at access networks • many things sharing your wireless LAN • Their scale and locations comes • special infra structure outdoor with complex concerns • Things have limitations – device/data handling, ownership – low processing power, memory, low – security, safety, privacy, capacity network application reliability • size IP packet comparable to available memory • at a compelling scale – sometimes battery operated – application development, – embedded: no UI deployment, management 13
But we had already WSN? IoT WSN • • System System – is platform: concurrent applications – … is the application at endpoints – open, extensible, interoperable • • Protocol Protocol – IP (+ higher) to endpoints (..) – application oriented – … on top of low resource networks – cross-layer optimization • Applications • Applications – use standard IP protocols – developed and optimized – developed separately along with the entire system • • Management Management – implicit, part of the application – IP management protocols – explicit, requires interfaces 14
And M2M? M2M IoT • • System System – is platform: concurrent applications – … is the application at endpoints – application-specific devices – open, extensible – closed • Protocol • Protocol – IP (+ higher) to endpoints – standardized, for low-resource – … on top of low resource networks networks • • Applications Applications – use standard IP protocols – classes – developed and optimized – developed separately along with the entire system • Management • Management – IP management protocols – explicit, built into protocols – explicit, requires interfaces 15
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