6LoWPAN, WIRELESS HART & WIRELESS USB

1. 6LoWPAN
Wireless HART
Wireless USB

2. 6LoWPAN

3. 6LoWPAN
IPV6 over Low Power Wireless Personal Area Network
 6LoWPAN is a simple low cost communication network
 It allows wireless connectivity in applications with limited power and relaxed throughput
requirements
 It provides IPv6 networking over IEEE 802.15.4 networks
 It is formed by devices that are compatible with the IEEE 802.15.4 standard and characterized by
 short range,
 low bit rate
 low power,
 low memory usage a
 low cost

4. Fig. 6LoWPAN

5. Working
 When a lower processing capability sensor node in a 6LoWPAN or so-called reduced function
device (RFD)
 RFD wants to send its data packet to an IP-enabled device outside the 6LoWPAN
 It first sends the packet to the higher processing capability sensor node or so-called full function
device (FFD) in the same PAN.
 The FFDs forward the data packet hop by hop to the 6LoWPAN gateway.
 6LoWPAN gateway then forward the packet to the destination IP-enabled device by using the IP
 address.
Applications:
 Automation
 Industrial monitoring
 Smart Home

6.  It adopts IEEE 802.15.4 standard PHY and MAC layers as its bottom layers while chooses IPv6 in its
network layer.
 There are total of 27 channels defined in the PHY layer.
 These channels are allocated into different frequency bands with varying data rates as showed in Table
below.

7.  Adding an adaptation layer between MAC layer and the network layer to achieve the header compression,
fragmentation and layer-two forwarding.
 LOAD protocol is a simplified on-demand routing protocol based on AODV.
 It is defined to be operating on top of the adaptation layer instead of the transport layer
Fig.6LoWPAN Protocol Stack

8.  The basic tasks provided by the MAC layer are beacon generation and synchronization
 It supporting PAN association and disassociation, managing channel access via Carriers Sense
Multiple Access with Collision Avoidance (CSMA/CA) mechanism
 IEEE 802.15.4 standard defined 4 frame structures for MAC layer:
 Beacon frame
 Data frame
 Acknowledgement frame
 MAC command frame
 A beacon frame is used by a PAN coordinator to transmit beacons
 Data frame is used for data transfers.
 The acknowledgement frame and the MAC command frame, are used for confirming successful frame
reception and handling all MAC peer entity control transfers respectively.

9. Wireless HART

10. WirelessHART
 WirelessHART is a wireless sensor networking technology based on the Highway Addressable Remote
Transducer Protocol (HART).
 It is a subset of the HART industrial instrument communication standard as of version 7, communicating
process data over 2.4 GHz radio waves.
 WirelessHART is a wireless mesh network communications protocol for process automation applications.
Fig. WirelessHART
Architecture

11. Working
 Each individual instrument in the HART wireless connection is connected through a mesh
network.
 Each individual instrument is connected to a common input and adjustment instruments.
 If an instrument is far from the gateway or the route is blocked, it can not connect to the
gateway. Although you can communicate with the gateway through other instruments.
 Therefore, each device in the mesh network can serve as a router for messages from other
devices.
 The purpose of a mesh network is to provide redundant data pathways in case of device failure
or changes in the environment interrupting radio communication between devices
 A network administrator responsible for configuring the network, scheduling communications
between devices, managing message routes, and monitoring the state of the network.
 Network Manager can be integrated into the gateway

12. Physical Layer:
 2.4 GHz to 2.5 GHz (“ISM” – Industrial, Scientific, Medical) signal band
 O-QPSK modulation (offset quadrature phase-shift keying)
 250 kbps data rate
 DSSS with frequency-hopping between 15 channels within that band for security and interference reduction
 TDMA bus arbitration, with 10-millisecond timeslots allocated for device transmission
Data Link Layer:
Network ID number uniquely identifies each WirelessHART network, allowing multiple networks to
overlap the same physical area
Network Layer:
 Mesh networking
 Signal repeating – devices may act as “repeaters” for other devices too far away from the master unit
 A Network Manager device determines communication routes between field devices.

13. Wireless USB

14. Wireless USB
 Wireless USB is a wireless technology which enables the high- speed computer peripheral
interface, USB, wireless.
 It is a wire replacement of existing USB technology using a Multi Band Orthogonal Frequency
Division Multiplexing radio technique.
 The physical layer is standardized under IEEE 802.15.3 PHY.
 The major WUSB promoters are HP, Intel, Microsoft, NEC Philips, & Samsung
 USB system can be described by three definitional areas:
 USB interconnect
 USB devices
 USB host

15. (A) USB interconnect :
The USB interconnect is the manner in which USB devices are connected toand communicate
with the host.
(B) USB Device :
Wireless USB devices which provide capabilities to the system, such as a printer,a digital camera, or
speakers
(C) USB Host :
 There is only one host in any USB system.
 The USB interface to the host computer system is referred to as the Host Controller.
 Host controllers are typically connected to PCs through an internal bus such as PCI.
 The Host Controller may be implemented in a combination of hardware or software.

16. Fig. Hub and Spoke topology

17. Topology
 Wireless USB connects USB devices with the USB host using a 'hub and spoke' model.
 The Wireless USB host is the 'hub' at the center, and each device sits at the end of a 'spoke'.
 Each 'spoke' is a point-to-point connection between the host and device
 It allows up to 127 devices to connect directly to a host and has a theoretical maximum speed and
range of from 480 Mbps at 3 meters to 110 Mbps at 10 meters.
Security:
 To protect sensitive transmissions from interception, WUSB provides 128-bit Advanced
Encryption Standard cryptography.
 WUSB provides an extra layer of security by enabling the host to randomly generate a one-
time secret AES encryption key and transmit it to a device via either a USB cable used only
for first-time setup or public-key encryption, in both cases to protect againstinterception