Communications & Networks WPANs/WBANscsce.uark.edu/~ahnelson/CSCE5013/lectures/lecture12.pdfBluetooth vs. BLE 14. ZigBee ZigBee { 915MHz or 2.4GHz spectrum, mesh-capable low-power

Communications & Networks –

WPANs/WBANs

Alexander Nelson

October 12, 2020

University of Arkansas - Department of Computer Science and Computer Engineering

Review – Wireless Communication

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WPAN/WBAN Communications

Low Power – Low Bitrate – Short Range Communication Protocols

Examples:

• Bluetooth

• Bluetooth Low Energy (BLE)

• Zigbee

• Z-Wave

• IrDA (Infrared)

• Thread

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WPAN Standards

IEEE 802.15 – Working group standardize WPANs

Standards shape the underlying technologies that the high-level

protocols must use

• 802.15.1 – Bluetooth

• 802.15.2 – Coexistence with other WLANs

• 802.15.4 – Low Rate WPAN (ZigBee, Thread, etc..)

• 802.15.5 – Mesh Networking

• 802.15.6 – Body Area Networks

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Bluetooth

Nils Rydbeck (Ericsson Mobile) & Johan Ullman – Develop

wireless headsets for communication

Operates in the 2.4GHz frequency spectrum

Uses frequency-hopping spread-spectrum communications

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Bluetooth – Frequency Hopping

Transmitter & Receiver hop channels with a known pseudo-random

code

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Bluetooth – Coexistence

Coexistence – 2.4 GHz spectrum is unlicensed, & many devices

may use the space

Example – Wi-Fi:

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Bluetooth – Coexistence

Two strategies:

• Avoid – Attempt to not collide with other communication

• Recover – Detect collision & resend data

Frequency hopping with short windows provide method for recovery

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Bluetooth – Coexistence

Avoidance can be implemented through intelligent selection of

channels

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Bluetooth – Specifications

Bluetooth 5.0: 2016/ 50MBps / 50 m range

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Bluetooth – Scatternet

Bluetooth implements a scatternet topology

Scatternets are groups of piconets

Piconets are small ad hoc networks of up to 7 active clients (up to

255 parked)

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Bluetooth – Connection & Encryption

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1https://www.slideshare.net/sara.naseem/bluetooth-2094234 11

Bluetooth – Profiles

Profiles – Protocols built on existing Bluetooth standard to define

data mode

Examples:

• HSP – Headset Profile

• HID – Human Interface Device

• SPP – Serial Port Profile

• A2DP – Advanced Audio Distribution Profile

• AVRCP – A/V Remote Control Profile

These protocols can specify data rate, what specific characters

mean, deadlines, and priorities

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Bluetooth Low Energy – BLE

Nokia identified usage patterns Bluetooth did not address in 2001

Project MIMOSA released in 2006 under name Wibree

Wibree wrapped back into Bluetooth in 2007, integrated in 2010

Bluetooth SIG released Mesh Profile for BLE in July 2017

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Bluetooth vs. BLE

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Bluetooth 5.1

Bluetooth standard updated January 2019

• Angle of Arrival & Angle of Departure for tracking devices

• Advertising Channel Index - Improve advertising channel

selections

• GATT Caching - Faster discovery of devices

• Periodic Advertising Sync Transfer - Devices that never intend

to connect can synchronize advertising packets

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ZigBee

ZigBee – 915MHz or 2.4GHz spectrum, mesh-capable low-power

WPAN

ZigBee Alliance released Specification 1 in 2005

ZigBee Cluster Library – 2006 Specification to standardize

commands and organize groups

Zigbee PRO – 2007 Specification for ease of use with large

networks

ZigBee Dotdot ‖ : – 2017 Replacement to cluster library, run over

other networks with Internet Protcol and connect with other

specifications such as Thread

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Z-Wave

Z-Wave – 900 MHz band mesh protocol, primarily for home

automation

Developed in 2001, released first series in 2003

Acquired by Sigma Designs in 2008

As of 2017, 1700 products are certified by the Z-Wave Alliance

Long operating range (300 feet outdoor)

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Thread

Thread Group alliance founded in 2014

Founded researchers from Nest Labs – now has many large

partners (Google, Samsung, Qualcomm, Silicon Labs, Tyco)

Implements 6LoWPAN with a connecting router (edge router)

Forward end-to-end WWW packets to mesh endpoints

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OpenThread

Open-source implementation of Thread

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802.11ah – Wi-Fi HaLow

Wi-Fi powered at lower frequency (900MHz, surprise!)

Signal propagates further & through walls better

Lower-bandwidth, lower power

Added to standard in 2017 – no commercial chipsets available yet

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