4. Internet of Things
● Everything that benefits from networking will eventually be connected
● Interoperability
● Legacy
● Technology is already there
● Universal identity, IPv6
● Endless applications
● Devices+Services
– Data collection, vizualization, smart control...
9. Wireless Technologies
Standard IEEE 802.15.4 Bluetooth Wi-Fi
Frequency 868/915MHz,
2.4 GHz
2.4GHz 2.4, 5.8 GHz
Data rate 250kbps 723 kbps 11 to 105 Mbps
Range 10 to 300 m 10m 10 to 100m
Power Very Low Low High
Battery Operation Alkaline
(months to years)
Rechargeable
(days to weeks)
Rechargeable
(hours)
10. IEEE 802.15.4
● Low power, low data rate wireless standard
● It is not Zigbee
● MAC and PHY layer protocol
● Operates on several bands:
– 2.4 GHz ISM band, 915 Mhz, 868 MHz
● Local regulations
● MTU: 127 Bytes per frame (including headers)
● Data rates upto 250kbps
11. 6LoWPAN
● IPv6 over Low power Wireless Personal Area Networks
● RFC 4944 and RFC 6282
● Adaptation layer
● Header compression
– Stateless or context-based compression
– Compression of addresses
● Neighbor discovery
● IPv6 MTU: 1280 bytes, 802.15.4 MTU: 127 bytes.
– Fragmentation and Reassembly
● IPv6 header overhead: 802.15.4 MAC header upto 25-bytes + 40-byte IP header +
8-byte UDP
12. CoAP
● Constraint Application Protocol
● Accepted as RFC in July 2013
● RESTful web protocol
● GET, POST, PUT, DELETE methods
● Simple Request/Response exchange
● URI (Uniform Resource Identifiers) support
– coap://test.com:<port>/~temperature/sensor1.xml
● Proxy to/from HTTP
● < 10 bytes header
● Simple caching
● Libcoap, contiki, Firefox CoAP plugin
13. EXI
● Efficient XML Interchange
● Standardized by W3C, March 2011
● Compression of XML encoded content
● Compact XML representation
● High processing performace
● OpenEXI,EXIficient
14. Working groups
● 6lowpan (IPv6 over LoWPANs)
– 2007: RFCs 4919 (requirements) and 4944 (6LoWPAN
standard)
– 2011: RFC 6282 as an update for RFC 4944
● Roll (routing over low power and lossy networks)
– 2011: RFC 6206 (Trickle protocol)
– 2012: RFCs 6550 (RPL) and 6552 (Objective Function
Zero)
● Core (constrained RESTful environments)
– 2013: CoAP (draft-ietf-core-coap)
16. Operating Systems
● Contiki
– less than 10kB RAM and 30 kB ROM.
– Highly portable, multithreaded, preemptive
– Supports IPv6, 802.15.4, and 6LoWPAN
● Tiny OS
– nesC language, non preemptive, eventdriven,
● Nano-RK
– less than 2kB of RAM and 18kB of ROM
● Mantis, LiteOS, FreeRTOS
18. Thanks
"One machine can do the work of fifty ordinary men. No machine can do
the work of one extraordinary man."
- Elbert Hubbard
19. References
● Jari Arkko,Building the Internet of Things
http://www.arkko.com/publications/vitel_arkko.pdf
● G. Montenegro, N. Kushalnagar, J. Hui, D. Culler. Transmission of IPv6 Packets over IEEE 802.15.4
Networks. RFC 4944, IETF, September, 2007
http://tools.ietf.org/html/rfc4944
● IERC - Internet of Things European Research Cluster - 3rd edition of the Cluster Book
http://www.internet-of-things-research.eu/pdf/IERC_Cluster_Book_2012_WEB.pdf
● http://isoc.org/wp/ietfjournal/?p=2066
● https://www.sics.se/search/content/contiki
● Adam Dunkels. Contiki Crash Course
http://www.ee.kth.se/~mikaelj/wsn_course/contiki-course-kth-9oct2008-draft.pdf
● RFC 4838: Delay-Tolerant Networking Architecture
http://tools.ietf.org/html/rfc4838
● Efficient XML Interchange Working Group
http://www.w3.org/XML/EXI/
● http://www.w3.org/TR/exi-evaluation/