Communication Research Labs Sweden AB. Course element content for Ad hoc Lecture 1 (Ad hoc concept and networking overview) Ad hoc concept Ad hoc basic

Communication Research Labs Sweden AB


Course element content for Ad hoc

•Lecture 1 (Ad hoc concept and networking overview)•Ad hoc concept•Ad hoc basic functionality•Background/ history•Ad hoc possible usage areas•Wireless Sensor Networks (WSN)•Networking: OSI, Protocols, routing, TCP/IP•Project description (briefly)

•Lecture 2 (Networking and routing in depth)•Networking: OSI, Protocols, routing, TCP/IP•TCP/IP in depth•Routing protocols: purpose, conceptual function and review•Standardization work: IETF, IEEE current protocols•Additional ad hoc routing features

•Lecture 3 (Advanced concepts)•ARP, MAC layer•Quality of Service (QoS): SNR, Bandwidth constraints, Neighbor solicitation errors•IPv6 (briefly)•Security issues for ad hoc networks (briefly)

Ad hoc communication: Concept, OSI and TCP/IP OSI and TCP/IP


The Concept of ad hoc networks

What is a mobile ad hoc network?

A self-organizing network of mobile nodes communicating using multi-hop routing. The

nodes act as both hosts and routers.

Ad hoc communication: Concept and function



A self-organizing wireless network of mobile nodes communicating using multi-hop routing. The nodes act as both hosts and routers.

Experienced communication above network level

Real communication




communication

distance

0 1 2 3 4 5(units)

ad hoc ad hoc

Usage areas of ad hoc network?school example



Ad hoc routing

AB

NodesSource node (A)Destination node (B)

Creates networks without any existing infrastructure

Ad hoc communication: Concept and functionality



Animation of the functionality of a mobile Ad hoc network



• Wireless Sensor Networks

• WiMAX and WLAN Mesh networks

• Local WLAN networks

• Mobile coverage range extension

• Construction sites

• Commercial use - conferences, exhibitions,…

• Education - virtual classrooms

• Festivals, concerts,...

• Gaming industry

• Mobile Telephony

Ad hoc networking usage?

Ad hoc communication: Usage areas

ad hoc


Ad hoc & Distributed SystemsAd hoc communication:

Creates possibility for wireless (mobile?) units to find each other and establish communication, due despite lack of infrastructure and uni-directional communication (each node not within range to all other nodes)

Distributed systems:

System which consists of numerous units which cooperates and communicates together “in all”. Arbitrary number of systems- and working processes. Some form of common distributed control that affect the whole system, which is NOT centralized!


Ad hoc applications on “regular” computer platforms


• Ad hoc and Mesh technology maturity is at the same stage as WLAN were in the middle of the 90's; they work, but they're expensive and proprietary.

WLAN ad hoc networking

Today's office WLAN

AP


• Ad hoc and Mesh technology maturity is at the same stage as WLANs were in the early 90's; they work, but they're expensive and proprietary.

WLAN ad hoc networking

Tomorrows WLAN with client ad hoc routing

AP


• Easy deployment of WiMAX Access Points• Less pre-configuration• Redundant communication

WiMAX Mesh networks(mesh backhaul extensions for MWAN)


Ad hoc routing History

Protocol Original paper• GB

Gafni-Bertsekas [Gafni1981]

• DBF 87 Bertsekas1987a] Distributed Bellman-Ford 87

• DSDV 94 [Perkins1994][Perkins1996]Highly Dynamic Destination-Sequenced Distance-Vector Routing

• DSR 96 Dynamic Source Routing [Johnson1996][Broch1998]

• AODV [Perkins1997]

• Ad Hoc On-Demand Distance Vector Routing Protocol


source

destination



Ad hoc redundancy scenario

Objective: Mp3 streaming over redundant 4 hopsPurpose: Demonstrate the strength of ad hoc networks.

source destination

Link failure

Link failure Link failure

81

2

3

4

6

7

5


Ad hoc basic functionality

•All communication wireless•No preexisting infrastructure needed•Dynamic topology•Rapidly deployed/started •Self healing•Highly redundant•Whispering•Power saving

Ad hoc communication: Concept of ad hoc networks

Advantages



•All communication wireless•No preexisting infrastructure needed•Dynamic topology


Advantages



•Rapidly deployed/started •Self healing•Highly redundant


Advantages



•Whispering•Power saving


Advantages

If the range of a radio transmitter is reduced by a factor f, the energy

consumed is being reduced by f^2, i.e. half the range reduces the energy by a

factor of 4.

(+ extra computational power for each middle node's CPU)


Ad hoc compatibility examples• WLAN: E.g. (802.11x) with network interface in “ad hoc mode” p2p

• ZigBee™( IEEE 802.15.4 ): Includes ad hoc functionality within its standard (Based on an AODV implementation. What that is, we will go through deeply during lecture #2)

• Bluetooth ™ : Is often referred to as ad hoc, for its functionality of “plug and play” connect ability with other Bluetooth equipments.Bluetooth IS NOT compatible for ad hoc routing due to its Master<-> Slave behavior in piconets. Despite its capability of piconets, and scatternets.

• WLAN AP´s Proxim, Cisco, Firetide

• Other radio interfaces…


Reasons for using Mesh and ad hoc• Price: Each mesh node runs both as a client and as a repeater potentially

saving on the number of radios needed and thus the total budget.• Ease and simplicity: If you have a box that is pre-installed with wireless mesh

software and uses standard wireless protocols such as 802.11b/g, the setup is extremely simple. Since routes are configured dynamically, it is often enough to simply drop the box into the network, and attach antennas.

• Organization and business models: The decentralized nature of mesh networks lends itself well to a decentralized ownership model.

• Network robustness: Greater stability in the face of changing conditions or failure at single nodes.

• Power: Low power requirements, meaning that they can be deployed as completely autonomous units with solar, wind, or hydro power for WSN Motes.

• Integration: Mesh hardware is typically small, noiseless, and easily encapsulated in weatherproof boxes. This means it also integrates nicely outdoors as well as in human housing.

• Reality fit: Reality rarely comes as a star, ring, or a straight line. In difficult terrain -- be that urban or remote -- where not every user can see one or few central points, chances are she can see one or more neighboring users.


Limitations• Network bandwidth

• Security

• Node capacity

• Network delays

• Quality of Service guaranties

• Communication range

• Network traffic control

(network administrator)



Existing ad hoc Routing Protocolsa selection…

ZHLS

BSR

HSR

SSR

GSR

FSR

DSR-MB

DSRFLOW

MOR

FORP

LAM PAMAS

CAMP

LUNAR

LANMAR

MAODV

WRPZRP

BRPMZR

LBM

CBMDCMPODMRP

ADMRRDMAR

DDMFGMP

FQMMSRMP

DSDVPLBR

CEDAR

DREAMIMEPMCEDAR

DBF

MRGRHSLS

STAR

TBRPF

CBRP

LAR

PARO

IARP

HARP

GPSALGLS

CGSR

GeoGRID

LMRTORA

AMRISMMRP AMRoute

IERPDDR

LBR

ABR

ISAIAHARA

CHAMP

ABAMLCA

GeoTORA

DSR

AODV

OLSR


Routing / Mobility Management

Proactive Routing Reactive Routing

• Continuously updates the network topology

• Requested routes are immediately available

• Network resources are wasted

• Route discovery on demand• Might cause some initial delay• Consumes less network

resources• Silent network


Routing / Mobility ManagementHybrid Routing

• Makes use of both the techniques of proactive and reactive routing

• a few (one or more), nodes in each “proactive zone”

• More resource is devoted to the topology update of nearby, and

• more frequently used, parts of the network.

• scalability to the network, but brings more complexity to the algorithm.

Clustering

• Clustering of nodes• control structure for the network to

accommodate to property changes in the network

Ad hoc communication: OSI, TCP/IP, Routing


Movie on TCP/IP Networking


Technical presentation of Wireless Sensor Networks

(WSN)


• Industrial Control and Automation

• Environmental monitoring

• Residential Control and Automation

• Advanced Automated Meter Reading

• Healthcare

• Security and Surveillance / Border protection/ Drug/law enforcement/ Counter-terrorism

• Transportation

• Home and office

• Logistics

• Woodland fires

Ad hoc communication: Usage Areas

Sensor Networks


• Environmental monitoring for chemicalor biological substances.

• Long lasting surveillance of large geographic areas for vehicles and personnel e.g. border protection.

• Easy deployed networks for temporary surveillance.

Sensor Networks


Distributed systems related to WSN

WSNs are composed of a large number of sensor nodes, therefore, an algorithm for a WSN is implicitly a distributed algorithm.

Communication Research Labs Sweden ABCommunication Research Labs Sweden AB

The concept of Ad hoc routing

A self-organizing wireless network of mobile nodes communicating using multi-hop routing.

The nodes act as both hosts and routers.

Experienced communication

Real communication


Sensor (type A) equipped with wireless communication device

Sensor (type B) equipped with wireless communication device

Sensorer:TemperatureMoistureAccelerationIR, motion detectorGases

….


100μW 1 mW 10 mW 100 mW 1 W 10 W 100 W 1000 W

Mote Handheld Mobile Desktop Server

Low-power sensor nodes requires sophisticated wireless communication protocols, medium access control and data

dissemination algorithms in conjunction with ultra low-power microcontrollers and advanced radio transceivers to achieve a system lifetime of several years with only 2 AA 3V Lithium

batteries!

Energy consumption in Motes


MOTES OS platformsTinyOS

A small, open source, energy efficient, software

operating system developed by UC Berkeley. The source code and software development tools are

publicly available at:http://webs.cs.berkeley.edu/tos

Contiki Contiki is an open source, highly portable, networked, multi-tasking operating system for memory-constrained systems. The source code and software development tools

are publicly available at:http://www.sics.se/~adam/contiki/

Protothreads provide linear code execution for event-driven systems

implemented in C.

uIP is an implementation of the TCP/IP protocol stack, developed at SICS, intended for small 8-bit and 16-bit microcontrollers.


MOTES Hardware platforms

Intel iMOTE

Scatterweb ScatterNode

Telos TMote

Crossbow Micadot

Crossbow Mica2Shockfish TinyNode

Scatterweb ESB

BTNode


MOTES: Software development challenges

• Memory constraind platforms• Medium Access Control (MAC): time synchronization and deep sleep• Ad hoc routing: Routing strategy – speed, robustness, energy

preservation• Routing table update VS energy and consumption• OSI model and Cross layer interactions


WSN technical Gaps and additional challenges…

• Sensor Calibration• Power Efficiency• Energy harvesting• New Sensors and Low-cost

devices• Miniturization• Context-aware MAC and Routing• Clustering techniques• Data Storage and Search• Multiple sinks

•Scalability•Quality of Service•Robustness•Mobility•Real-time•Localization•Operative systems•Programming models•System integration•Modelling and analysis


MOTES Hardware metrics and characteristics

Mica2 Imote Tmote Sky ShockfishSize (mm2) 1856 900 2621 1200Speed (MHz) 7,37 12 8 8Prog Memory (kB) 128 512 48 48Data Memory (kB) 4 11 10 10Storage (kB) 512 10 1024 512External I/O 51 30 16 19On-board sensors 2 1 5 1Price (sek) 850 1150 975 1215

Mica2 Imote Tmote Sky Shockfish ESBFrequency (MHz) 916 2400 2400 870 868Data rate 38 723 250 152 115Sensitivity 101 80 94 121 101Range 150 30 125 200 200Setup Time (ms) 50 500 1 0 50Channels 4 79 16 10 5

Hardware characteristics requirements differ on wide range of metrics depending on the application.

Mobility, radio range, # of units, data rate, robustness, cost, memory need, energy preservation etc.


MOTES Hardware metrics comparisions..

Frequency (MHz)

Data rate

Sensitivity

Range

Setup Time (ms)

Channels

Mica2 Imote Tmote Sky ESB

Size (mm2)

Speed (MHz)

Prog Memory (kB)

Data Memory (kB)

Storage (kB)

External I/O

On-board sensors

Price (sek)

Mica2 Imote Tmote Sky

Frequency (MHz)

Data rate

Sensitivity

Range

Setup Time (ms)

Channels

Mica2

Frequency (MHz)

Data rate

Sensitivity

Range

Setup Time (ms)

Channels

Imote

Frequency (MHz)

Data rate

Sensitivity

Range

Setup Time (ms)

Channels

Tmote Sky

Frequency (MHz)

Data rate

Sensitivity

Range

Setup Time (ms)

Channels

ESB

Size (mm2)

Speed (MHz)

Prog Memory (kB)

Data Memory (kB)

Storage (kB)

External I/O

On-board sensors

Price (sek)

Mica2

Size (mm2)

Speed (MHz)

Prog Memory (kB)

Data Memory (kB)

Storage (kB)

External I/O

On-board sensors

Price (sek)

Imote

Size (mm2)

Speed (MHz)

Prog Memory (kB)

Data Memory (kB)

Storage (kB)

External I/O

On-board sensors

Price (sek)

Tmote Sky


ZigBee

• Communication protocol using small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPAN)

• First version of ZigBee was released in December 2004. (version 1.0)

• ZigBee Alliance - association of companies (>150)


IEEE 802.15.4 Standard

• Specifies the physical layer (PHY) and the medium access control (MAC) layer.

• Operates in 3 frequencies;• 868 MHz in Europe (20 kbit/s)• 915 MHz in the USA (40 kbit/s)• 2.4 GHz worldwide (250 kbit/s)


ZigBee networks

• ZigBee coordinator (ZC)Initializes the network and might bridge to other networks. There is exactly one ZigBee coordinator in each network. Assigns addresses to new devices.

• ZigBee Router (ZR)Can act as an intermediate router, passing data from other devices.

• ZigBee End Device (ZED)Contains just enough functionality to talk to its parent node. It cannot relay data from other devices.


ZigBee networks

• Topologies• Star

• Several ZED communicating directly to the ZC• Mesh

• Extended by use of ZR (full peer-to-peer communication)• Routing strategy based on AODV (Ad-hoc On-demand Distance

Vector)• Tree

• ZR using hierarchical routing strategy


ZigBee Stack

PHY

MAC

NWK

802.

15.4

Zig

Bee

All

ian

ce

APS

ZDOAF

APL

868, 915, 2400 HZ

Control access to radio channel, transmit beacon frames, synchronization

Network Layer:- mechanisms to join or leave network- route discovery and maintenance, relay msg- security

Application Layer:•AF – Application Framework

•Manufacturer-defined applications•ZDO – ZigBee Device Objects

•Defines device (ZC, ZR. ZED)•Discovers devices on network and determine what services they provide

•APS – Application Support Sub-layer•Match 2 devices based on their services•Interface between NWK layer and AF/ZDO


ZigBee Conclusion• Main Intentions of ZigBee is:

• Wireless networking standard for PAN (Personal Area Networks) to form self-configuring nodes

• Consumes less power and memory than Bluetooth and WiFi• Advantages

• Standardized protocols are necessary when multiple vendors has to interoperate

• Low price because of many manufacturers of chipsets• Disadvantages

• Each network depends on ONE ZC (Master Node / Central Node), implies lack of robustness

• According to standard: “ZigBee routers are generally presumed to be mains-powered devices”. (30uW during sleep, 33mW while active, 25mA when tranceiving). ZED can have battery life time up to 2 years. All indoor applications have main-powered ZR

• Standardized protocol makes it impossible to optimize system for specific applications (e.g. routing algorithms, MAC layer). Reduces life time for sensor networks.

Documents

Communication Research Labs Sweden AB. Course element content for Ad hoc Lecture 1 (Ad hoc concept and networking overview) Ad hoc concept Ad hoc basic