INTERNET OF THINGS COMMUNICATION PROTOCOLS

Szymon Słupik szymon.slupik@homersoft.com

IoT means Low Power Radio

Laptop computer 15W average, always on WiFi: 54Mbps +, streaming data Last mile: 10Mbps +

Presence sensor 15μW average (6 orders less!)

75mW transmission power 3ms transmission time @125kbps 1 message every 75 seconds

12 years on a CR2450 coin cell battery Forever on a 3x7cm photovoltaic @50lx (dim room)

Low Power Radio Protocols

Range between 10m and 100m (typical)

IEEE 802.15 (open / multi – vendor): Bluetooth Low Energy ZigBee 6LoWPAN

Other (closed / single – vendor) ANT / ANT+ Z-Wave EnOcean (ISO/IEC 14543-3-10)

Proprietary Hundreds / thousands of things

Radio Estate Properties

2.4GHz (globally unified but crowded) Bluetooth LE ZigBee 6LoWPAN ANT / ANT+

Sub–GHz: 868/902/915MHz (regional, low duty cycle) ZigBee 6LoWPAN Z-Wave EnOcean

433 MHz (globally unified) Proprietary (eg weather stations)

Bluetooth Low Energy

Bluetooth SIG: http://bluetooth.org

Bluetooth 1/2/3 = streaming media (audio etc.)

Bluetooth LE = sensors and actors („things”)

Bluetooth 4 = Bluetooth 3 & BLE (dual mode) Smartphones Not supported on Android today

Only via proprietary (but open) stacks (Broadcom) Expected at GoogleIO 2013

Strict transport / open application layer

Star network topology No mesh / repeaters Energy efficient receivers

ZigBee

ZigBee Alliance: http://zigbee.org

Strict 802.15.4 MAC layer (868/915MHz / 2.4GHz) Common transport layer for proprietary applications

Application – layer open standards emerging ZLL (ZigBee Light Link) ZHA (ZigBee Home Automation) ZSE (ZigBee Smart Energy)

Ad-hoc mesh network topology Coordinators, repeaters, end nodes Destination – based routing (self healing)

Z-Wave

Z-Wave Alliance: http://z-wave.com

Controlled by Sigma Designs Requires membership, NDA

Physical layer varies by region (frequencies / radio bands)

Strict Application – layer protocol Command Classes guarantee interoperability Wide selection of compatible products

Source – based routing mesh Not self – healing Controllers, slaves

EnOcean

EnOcean Alliance http://enocean-alliance.org

Controlled by EnOcean GmbH (the company) Spin-off of Siemens AG

Designed for energy harvesting Mechanical, photovoltaic, thermoelectric True wireless: very popular for sensors

Physical layer varies by region (frequencies)

Application layer is optional Equipment Profiles

Star network topology Up to 2 repeaters between nodes

6LoWPAN

6LoWPAN IETF group RFC 4944

IPv6 over Low power Wireless Personal Area Networks MAC layer based on 802.15.4 (same as ZigBee)

Varies by region (frequencies)

Fragmentation, header compression Transport layer: UDP or TCP Vendor – specific „mesh under”

NXP (Jennic), TI, ZMDI

Standard addressing (IPv6) and security (IPsec, IKE)

No application layer standards yet

Potential to „rule them all” Including BLE, ZigBee (IP),

Z-Wave, PowerLine Communications

The question

Which one to choose?

The answer

It depends…

Reach: Bluetooth LE

Features: ZigBee

Compatibility: Z-Wave

Efficiency: EnOcean

Security: 6LoWPAN