bindhu ppt

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ISA Wireless Security, P. Fuhr 2

RAE Systems Inc. • Pervasive Sensing Company

based in Silicon Valley foundedin 1991

Capabilities – Radiation detection

• Gamma and neutron

– Chemical/vapor detection• Toxic gas, VOC, combustible

gas, oxygen, CWA,temperature, humidity, C02

– Redeployable sensor networks

– Mobile and fixed wirelessmonitors

– Cargo Container Sensor

Systems

Dr. Peter Fuhr, Presenter: 480+ publications&presentations in wireless sensornetworking arena. Old-timer in this area…etc etc.




Contributors A number of individuals have provided “content” for these slides. They

include: Wayne Manges, Oak Ridge National Laboratory

Robert Poor, Ember Pat Gonia, HoneywellHesh Kagan, Foxboro/InvensysKang Lee, NISTTom Kevan, Advanstar

Ramesh Shankar, Electric Power Research InstituteLarry Hill, Larry Hill ConsultingRob Conant, DustRick Kriss, XsilogyGideon Varga, Dept of EnergyJack Eisenhauser, EnergeticsMichael Brambley, Pacific Northwest National LabsDavid Wagner, UC-Berkeley

Undoubtedly, there are other contributors too (apologies ifyour name is not listed).




Wireless Sensor Networking…it’s not cellular telephony

…it’s not just WiFi...(and it just may be the next big thing)

Each dot represents one cell phone tower.

Wireless devices circa 1930




Sensor Market: $11B in 2001

Installation (wiring) costs: >$100B

Freedonia Group report on Sensors, April 2002

• Fragmented market platformopportunity

• Installation cost limitspenetration reducinginstallation costincreases market size

Slide courtesy of Rob Conant, Dust

Highly FragmentedSensor Market


http://slidepdf.com/reader/full/bindhu-ppt 9/136ISA Wireless Security, P. Fuhr 9

Outline:

1. Security? Who needs it?2. How is security achieved in a wired channel?3. The Situation for Wireless (its RF in an industrial setting.

Spectrum, modulation, encryption, spatial…)

4. Security within various Wireless Delivery Schemes(cellular, WiFi, 802.15.4, Bluetooth, others…)

5. An Integrated Solution6. The Big Review




Technology Group: Key Issues

• Security

– Jamming, hacking, and eavesdropping• Power

• Value (clear to customer)

• Interoperability

– Co-existence with other facility networks, sensors,collectors, technology

• True engineered solution (sensors, collectors, etc.)

• Assured performance & reliability/MTBA*

• Software infrastructure, data, & systems management

• Robustness (at least as good as wired)

• RF characterization (radios, receivers, environments)

*mean time between attention




A Favorite 2.4 GHz Antenna




WarDriving – 802.11 HotSpots in

Silicon Valley




The Question:Who needs security in a wireless channel

anyway!

The Answer:

We do. So…How do you provide the

appropriate level of security within theacceptable price and “inconvenience” margin

-> Risk Management!



H k U i




•Chinese Hacker Group working to advance

and in some cases impose it’s political agenda •During the spring of 2001, Honker Unionworked with other groups such as the ChineseRed Guest Network Security Technology

Alliance

Honker Union

•Hackers were encouraged to "...make use of their skills for China..." Wired.com

Denial of Service Attacks

•Website Defacement

•E-mailing viruses to US Government Employees

•“KillUSA” package

Attack Methods:




Cyberwar • Cyber attacks and web defacements

increased dramatically after the start of thewar against Iraq.

• More than 1,000 sites were hacked in thefirst 48 hours of the conflict, with many of the attacks containing anti-war slogans.

• Security consultants state that the war against Iraq made March the worst month

for digital attacks since records began in1995.




The Question:Who needs security in a wireless channel

anyway?

The Answer:

Everyone.




Layered Communications

A few details…




Wired Data Security - Encryption

The “traditional” method involved encrypting the data prior totransmission over a potentially insecure channel. The level of protection rests on the encryption algorithm. (There are a fewother factors…such as the physical media.)

Slide courtesy of Wayne Manges, ORNL




Outline:

1. Security? Who needs it?2. How is security achieved in a wired channel?3. The Situation for Wireless

4. Security within various Wireless Delivery Schemes(cellular, WiFi, 802.15.4, Bluetooth, others…)





Wireless Buildings

Key to success: reduced installation costs

From many perspectives, THIS is what a wireless sensor network can provide.

Slide courtesy of Pat Gonia, Honeywell




E(t) = A(t) cos[ t + (t)]

Modulation

Amplitude Modulation (AM)

info is in A(t)

Frequency Modulation (FM)

info is in

Phase Modulation (PM)

info is in (t)

Phase = 0o

Phase = 180o

Phase = 270o

Phase = 360o

(or back to 0o)

Different vendors use

different schemes - and they

are not interoperable.




The FCC Frequency Assignment

Different vendors may use

different frequencies within

the various ISM bands

(green in the diagram).

The ISM bands most commonly used are at 433, 915 and 2400 MHz.




Multiple Sensors Sharing the Medium:

Multiplexing. FDMA, TDMA and CDMA




Binary Signaling Formats

• Used to Improve DigitalSignal Reception andDecision

• NRZ: Non-Return to Zero

• RZ: Return to Zero

• Unipolar: Only one sideof 0V

• Bipolar: Both sides of 0V

• Manchester: Bi-Phase(“0” in left 1/2 time slot,

“1” in right)




Narrowband or Spread Spectrum? Narrowband uses a fixed carrier frequency, F0.

The receiver then locks onto the carrier frequency, F0.

Easy to implement (inexpensive).Prone to jamming or interference (two transmitters at thesame carrier frequency, F0.

Least secure modulation scheme.



N b d S d S t ( t ) ?




Narrowband or Spread Spectrum (cont.) ?

Direct Sequence Spread Spectrum uses a fixed carrier frequency, F0 but interleaves the data with a precise mathematical 0/1 data

sequence. (This increases the length of the transmitted informationvector making it longer). The information is replicated many timesthroughout the bandwidth, so if one “lobe” of the information is

jammed, the remainder “gets through”. Highly robust technique.

The receiver then locks onto the carrier frequency, F0 receives thesignal and then must ―undo‖ the interleaving.

More difficult to implement (more expensive).

Most complicated scheme (of these presented).

Most secure modulation scheme.

DIRECT SEQUENCE SPREAD SPECTRUM SIGNALS




Data

PN Clock

Data

DataClock

Carrier

±1

Local PN ClockLocal

Carrier

±1

±1

Frequency

PowerSpectralDensity

fc Frequency


fc Frequency


fc

DIRECT-SEQUENCE SPREAD-SPECTRUM SIGNALS

Narrow spectrum at output of modulator before spreading

Spectrum has wider bandwidth and lower power density after spreading with PN sequence (PN Rate >> Data Rate)

Original narrowband, high power density spectrum is restored if local PN sequence is same as and lined up with received PN sequence

RFI“Spread”

RFI

PhaseDemod

NarrowBP Filter

WideBP Filter

PN SequenceGenerator

PN SequenceGenerator




Narrowband or Spread Spectrum (cont.) ?

Which isbest?

Each has its pluses and minuses…and each scheme has its share of die-hard advocates and/or naysayers!

From a security standpoint, DSSS is best.

Different vendors use these

(and other) schemes at

different frequencies within

the various ISM bands.




No Matter What…Its Just an

Electromagnetic Field

A(t): amplitude of the wave

w: radian frequency of the wave

f(t): phase of the wave

E(t) = A(t) cos[ t + (t)]




The RF ―Footprint‖ Network “Size”

Personal Area Network: typical radiated power: 0 dBm, size: 10m

Local Area Network: typical radiated power: 20 dBm, size: 100m

Wide Area Network: typical radiated power: >30 dBm, size: >2000m

There are SO many technical questions: such as




Network Topologies?

Bus Network

Tree Network

Star Network

Ring Network

Ad Hoc Network

There are SO many technical questions: such as…




The Real World Presents theWireless Channel with Multipath andAttenuation…and…

M lti thReal World:




Multipath

The Cause

The Effect

Real World:

Real World:




Atmospheric Attenuation at 2.4 GHz Real World:

Rayleigh Fading @ 2.4GHz

Real World:




Signal Attenuation at 2.4 GHz Real World:

Real World:




And Signal-to-Noise Ratios really do

matter!

Real World:

Anecdotal Evidence: As Frankfurt has increased thedeployment of 2.4 GHz wireless surveillance cameras,the background Noise level has increased by 12 dB.(This plays havoc with the BER or for fixed BER, theoverall data rate,)

Which Frequency is Best?Real World:




Which Frequency is Best?

Notice that the operation at 2.45 GHz isWORSE than at 900MHz (which is worse

than 433 MHz).

ALERT! ALERT!!

O tli




Outline:

1. Security? Who needs it?2. How is security achieved in a wired channel?3. The Situation for Wireless (its RF in an industrial setting.


4. Security within various Wireless DeliverySchemes (cellular, WiFi, 802.15.4, Bluetooth, others…)





The Wireless Market

S H O R T

<

R A N G E

>

L O N G

LOW < DATA RATE > HIGH

PAN

LAN

TEXT GRAPHICS INTERNET HI-FIAUDIO

STREAMINGVIDEO

DIGITALVIDEO

MULTI-CHANNELVIDEO

Bluetooth1

Bluetooth 2

ZigBee

802.11b

802.11a/HL2 & 802.11g




Bluetooth vs. the Rest (cont‘d)

802.112.4 GHz, DSSS11 chips/bit11Mbps+20 dBm

50m128 devicesCSMA/CAOptional WEPOptional

HomeRF2.4GHz, FHSS50 hops/s1 Mbps+20 dBm

50m128 devicesCSMA/CAOptionalOptional

Bluetooth2.4 GHz, FHSS1000+hops/s1Mbps0, +20dBm

1-10m, 50m8 devices,PiconetEncryptionYes

ParameterTechnology

Data RatePower

RangeTopology

SecurityVoice Channel

ZigBee (proposed)2.4 GHz,DSSS15 chips/bit40 kbits/s0dBm

100m100s devices,CSMA/CANot yetNo

Bluetooth – aka IEEE 802.15.1

ZigBee – aka IEEE 802.15.4




Side by Side




802.11?

The Worldwide View of the 802.11 Spectral




The Worldwide p

Space

R di d Fi ld f i l AP




Radiated Field from a single AP(Kansas City)




20dB Attenuation Profile for Univ of KansasEng Bldg., Mesh and AP deployments




WEP

• The industry‘s solution: WEP (Wired Equivalent Privacy)

– Share a single cryptographic key among all devices

– Encrypt all packets sent over the air, using the shared key – Use a checksum to prevent injection of spoofed packets

(encrypted traffic)




Early History of WEP

802.11 WEP standard released1997

Simon, Aboba, Moore: some weaknessesMar 2000

Walker: Unsafe at any key sizeOct 2000

Borisov, Goldberg, Wagner:

7 serious attacks on WEP

Jan 30, 2001

NY Times, WSJ break the storyFeb 5, 2001




Subsequent Events

Jan 2001

Borisov, Goldberg, Wagner

Arbaugh: Your 802.11 network has no clothes

Mar 2001

Arbaugh, Mishra: still more attacks

Feb 2002

Arbaugh: more attacks … May 2001

Newsham: dictionary attacks on WEP keysJun 2001

Fluhrer, Mantin, Shamir: efficient attack on way WEP uses RC4Aug 2001




WEP Attack Tools

• Downloadable procedures from the Internet

– To crack the Key:

• AirSnort

– http://airsnort.sourceforge.net

• WEPCrack

– http://sourceforge.net/projects/wepcrack/

– To brute force enter into WLAN,

• THC-RUT

– http://www.thehackerschoice.com/releases.php



A i




WPA – Data Encryption

– WPA uses Temporal Key Integrity Protocol (TKIP) - stronger

data encryption, addresses known vulnerabilities in WEP.

•TKIP chosen as primary encryption cipher suite -

Easily deployed and supported in legacy 802.11b

hardware compared to other available cipher suites.

– TKIP based on RC4 stream cipher algorithm, surrounds WEPcipher engine with 4 new algorithms,

1. Extended 48-bit Initialization Vector (IV) and IV sequencing rules

(compared to the shorter 24-bit WEP RC4 key).

2. New per-packet key mixing function.

3. Derivation and distribution method - a.k.a. re-keying.

4. A message integrity check (MIC) - a.k.a. „Michael‟ , ensures messageshaven‟t been tampered with during transmission.




BlueTooth- Some Specifications

• Uses unlicensed 2.402 - 2.480 GHz frequency range

• Frequency hopping spread spectrum 79 hopsseparated by 1 MHz

• Maximum frequency hopping rate: 1600 hops/sec

• Nominal range: 10 cm to 10 meters

• Nominal antenna power: 0 dBm

• One complete Bluetooth data packet can betransmitted within each 625 msec hop slot.

Potential Bluetooth Markets




Potential Bluetooth Markets

Bluetooth Market Forecast




Nov‘03: 100M Bluetooth compliant devices worldwide

Bluetooth Protocol Stack




Bluetooth Protocol Stack• Adopted Protocols

– PPP(Point-To-Point Protocol)

– TCP/UDP/IP

– OBEX-Session Protocol for IrDA(Infrared Data Association)

– Contents Fromat(e.g. vCard, vCalendar) – WAP-Wireless Application Protocol

Bluetooth Security




Bluetooth Security

• Supports Unidirectional or Mutual Encryption based

on a Secret Link key Shared Between Two Devices• Security Defined In 3 modes:

– Mode1- No Security

– Mode 2 - Service Level Security: Not Established

Before Channel is Established at L2CAP – Mode 3 - Link Level Security: Device Initiates

Security Before LMP Link is Setup

• Devices and Services can be Set for Different Levels of Security

– Two Trust Levels are Set for Devices• Trusted Device: Fixed Relationship and Unrestricted

Access to All Services

• Untrusted: No Permanent relationship and RestrictedServices




Bluetooth Security

• Devices and Services can be Set for Different Levelsof Security

– Two Trust Levels are Set for Devices

• Trusted Device: Fixed Relationship andUnrestricted Access to All Services

• Untrusted: No Permanent relationship andRestricted Services

Bluetooth Security




Bluetooth Security• 3 Levels of Service Access

– Require Authorization and Authenication – Require Authentication Only

– Default Security for Legacy Applications




But is this Wireless Link Secure?

Newsflash: Jan 2001: Norwegian “hackers” crack a

Bluetooth transmission

Analysis of a BlueTooth Transmission




y

High overhead?




802.15.4/Zigbee?




IEEE 802.15.4 standard

• Includes layers up to and including Link Layer Control

– LLC is standardized in 802.1

• Supports multiple network topologies including Star, Cluster Tree and

Mesh

IEEE 802.15.4 MAC

IEEE 802.15.4 LLC IEEE 802.2

LLC, Type I

IEEE 802.15.4

2400 MHz PHY

IEEE 802.15.4

868/915 MHz PHY

Data Link Controller (DLC)

Networking App Layer (NWK)

ZigBee Application Framework

• Features of the MAC:Association/dissociation, ACK,frame delivery, channel accessmechanism, frame validation,guaranteed time slot management,beacon management, channel scan

• Low complexity: 26 primitivesversus 131 primitives for802.15.1 (Bluetooth)

PHY overview




PHY overview• Speed

– 20, 40 or 250 kbps

• Channels – 1 channel in the 868MHz band

– 10 channels in the 915MHz band

– 16 channels in the 2.4GHz band

• Modulation

– BPSK (868MHz/20kbs) – BPSK (915MHz/40kbps)

– O-QPSK (2.4GHz/250kbps)

• Coexistence w/

– 802.11b DSSS

– 802.15.1 FHSS

– 802.15.3 DSSS




MAC overview

• Security support• Power consumption

consideration

• Dynamic channel

selection

• Network topology

– Star topology

– p2p topology – cluster-tree network

topology

Device classification




Device classification• Full Function Device (FFD)

– Any topology

– Can talk to RFDs or other FFDs – Operate in three modes

• PAN coordinator

• Coordinator

• Device.

• Reduced Function Device (RFD) – Limited to star topology

– Can only talk to an FFD(coordinator)

– Cannot become a coordinator

– Unnecessary to send largeamounts of data

– Extremely simple

– Can be implemented usingminimal resources and memorycapacity




Transmission management

• Acknowledgement

– No ACK

– ACK

– Retransmission – Duplicate detection

• Indirect transmission




Security

• Unsecured mode

• ACL mode

– Access control

• Secured mode – Access control

– Data encryption

– Frame integrity

– Sequential freshness

S l bl S it




Scalable Security

• Assume the attacker can deploy own nodes (cancreate a ―ring‖ at some distance fromcontroller)[Wisenet 2003]

• Enemy nodes ―mimick‖ the mesh nodes; theyACK the ―health inquiry‖ as if everything was OK – but they do not forward to the rest of the net

• The rest of the network is virtually cut off frominspection by controller

• Need secure key and a random seed that changesat each round

Wh t Ab t




What About:

1451.5?1xRTT?

SAT?CDPD?

Others?

No time this morning!



I t t d I d t i l N t k ?

There are SO many technical questions: such as…




Integrated Industrial Networks?

If the sensor network is to integrate into an industrial setting, then youshould be cognizant of the Industrial Networking arena.

Industrial Device Network Topology




• Typically, three layers of networking make up enterprisewide networks. Ethernet

acts as the company's intranet backbone, and it's linked to controllers or industrial PCs, which supply strategic data to the enterprise. An industrialnetwork, or fieldbus, links sensors and smart devices. A gateway (not uncommonin a large system with lots of devices) links devices that have only RS-232 or RS-485 ports to the fieldbus system.

I d i l D i N k




Industrial Device Networks• General characteristics for industrial device

networks have arisen.

• Obviously the complexity of the network increases as thefunctionality is increased.

Cl ifi i f I d i l




Classification of Industrial

Networks

• Three logical groupings of instrumentation

networks used in an industrial setting.

• There are over 100 different proprietarynetworks in the field.



Network Positioning




-

F u n c t i o n a l i t y

+

Ethernet TCP/IP

- Cost +

+

C o

m pl exi t y

-

- Data +

DeviceNet Other CAN SDS

Fieldbus H1Profibus-PAModbus HART

Profibus-DP

Interbus-S Remote I/O

Profibus-FMS

Data Highway+ Modbus Plus

ASi, Seriplex,Hardwiring, RS485 etc.

ControlNet Foundation Fieldbus H2




Too Focused on Internet Issues?

• Myth #1: Our SCADA/PLC/DCS is safe if

we don‘t connect to the Internet.

• Myth #2: Our Internet firewall will protectour control systems.

• Myth #3: Our IT department understands

process control issues and security.

Is Industrial Comm Security Too




Focused on Internet Issues?

Field Devices

ControlNetwork

SCADAProgramming Stations

PLC PLC

RemoteEngineering

ProductionPlanning

Manufacturing Logistics

EnterpriseResource Planning

ProcessHistorian

Enterprise Network

Internet

Firewall

Ethernet

Production Networks

HandheldOperatorTerminal

Modem

OEM

802.11WLAN

Source (used by permission): Interface Technologies, Windsor, CT, 2002

WarDialingAttack



Bit Rate vs. Quality of Service




How Many

Bits are

Needed?

The more bits

you xmit,the morepower youconsume!

Coding vs. Quality of Service




g y

Is Coding

Really

Necessary?

Direct Sequence Spread Spectrum




Comparing Wireless




Comparing Wireless

Tech. Range RF

Power

Battery

life

Number

s In

Area

DSSS Medium Low longest High

FHSS Long High Short Medium

UWB Medium Lowest short High

Technology Beats Marketing in




Performance!Technology versus Attributes

Summary Chart

Technology

Attribute

DSSS

FHSS

UWB

CDMA

TDMA

FDMA

Low

Power

Designs

Mobile

Ad Hoc

Networks

Power

Harvesting

Embedded

Intelligence Diversity FEC

Open

Standards

BPSK

QPSK

M-ary

900MHz

2.4GHz

5.8GHz

Long Range NA NA NA yes NA NA yes yes NA NA 900MHz

Plug-and-Play DSSS CDMA NA NA NA NA NA NA yes NA NALong Battery life FHSS FDMA yes NA yes yes yes yes NA M-ary 900MHz

Low RFI risk DSSS NA yes yes NA yes yes NA NA NA 5.8GHz

Self Locating DSSS CDMA NA NA NA yes yes NA NA NA 5.8GHz

Secure UWB CDMA yes NA NA yes yes NA NA NA 5.8GHz

High throughput UWB NA NA NA NA yes yes yes NA M-ary 5.8GHz

non line-of-sight UWB NA NA yes NA NA yes NA NA NA 900MHz

robust connections DSSS CDMA NA yes NA NA yes yes NA BPSK 5.8GHz

low cost FHSS FDMA yes NA NA NA NA NA yes BPSK 900MHz

small size FHSS TDMA yes NA NA NA NA NA NA BPSK 5.8GHz



Optimization of Security vs Cost




Optimization of Security vs. Cost• Risk reduction is balanced against the cost of

security counter measures to mitigate the risk.

Security Level

Cost ($)

Cost of Security

Countermeasures

Cost of Security

Breaches

Optimal Level of Security

at Minimum Cost




There‘s lot of ―Wireless‖

• From cellphones to PDAs to WiFi to

Satellite-based




Wireless LAN Standards

Existing/Developing




Existing/Developing

IEEE 802.11 Standards• 802.11-

• 802.11a –

• 802.11b –

• 802.11e –

• 802.11f –

• 802.11g –

• 802.11h –

• 802.11i –

• 802.1x – • 802.15 –

• 802.16 –

Frequency Hopping/DSSS

54Mbps / HyperLAN

(1999) 11Mbps

Quality of Service

Point 2 Point Roaming

(2003) 54Mbps

European Inspired Changes

(Q2,2004) New Encryption Protocols

(Q2,2004) Port Based Network AccessPersonal Area Network (WPAN)

Wireless Metropolitan Area Network (WMAN)

Wireless Backbone for Inflight “Entertainment”




PicoCellBTS

PicoCellBTS

NoiseFloor Lifter

6 MCUGSM SERVER

On-Board Network Integration

SDU

…and we haven’t even touched on RFID!




There‘s lot of ―Wireless‖

• And it all needs to feel more Secure!

For a real review of networking




For a real review of networking

security… • Take Eric Byrnes ISA course IC32C…

Will History Repeat?




Will History Repeat?

analog cellphones: AMPS1980

1990

2000

analog cloning, scannersfraud pervasive & costly

digital: TDMA, GSM

TDMA eavesdropping [Bar]

more TDMA flaws [WSK]

GSM cloneable [BGW]GSM eavesdropping

[BSW,BGW]

Future: 3rd gen.: 3GPP, …

Cellular networks

802.11, WEP

2001

2002

WEP broken [BGW]WEP badly broken [FMS]

WPA

2000

1999

Future: 802.11i

2003

attacks pervasive

wireless networks

Proprietary systems

2002

1451, 802.15.4, TinyO

Future: ???

2003

sensor networks

wireless security: not just 802.11

PATRIOT A t




• PATRIOT (Provide Appropriate ToolsRequired to Intercept and Obstruct

Terrorism)• Legally classifies many hacking attacks

as acts of terrorism

PATRIOT Act

So… If Nothing else, at leastPLEASE d hi f WiFi




PLEASE do this for your WiFi

System!

WLAN Security Countermeasures• Conduct site survey

• Identify areas of signal strength and weakness

• Do a “walkaround” with NetStumbler

• Document and shut down rogue access points

• Document and shut down unauthorized wirelessNICs

• AND TURN ON SOME LEVEL OF THEPROVIDED PROTECTION!

Oh…




And don’t forget that as you layer in all of these wacky encryption schemes andCDMA and DSSS and…and… that it takes

some joules to actually implement this. Soif your wireless network has primepower(a.k.a. AC) you’re ok. But if you’re going

off a battery then it’s a tradeoff of security

versus Power Consumption YouChoose that one!

...and in the end...




...or...

Two potential forms of wireless sensor networks.

And they should both be secure!

HoneyBee with RFID

BumbleBee with RF xcvr

Outline:




1. Security? Who needs it?

2. How is security achieved in a wired channel?3. The Situation for Wireless (its RF in an industrial setting.


4. Security within various Wireless Delivery Schemes

(cellular, WiFi, 802.15.4, Bluetooth, others…) 5. An Integrated Solution6. The Big Review 7. Glossary and References

Glossary10BASE-T: IEEE 802.3 standard for a twisted-pair Ethernet network. 10 Mbps transmission rate over baseband using unshielded, twisted-

pair cable




pair cable.

802.11: The IEEE 802.11 standard defines both frequency hopping and direct sequence spread spectrum solutions for use in the 2.4-2.5 MHz

ISM (Industrial, Scientific, Medical) band.

802.11a: The Global System for Mobile Communications standard for worldwide wireless communications on wide area networks (WANs).

802.11b: The portion of the 802.11 specification that defines the 11 Mbps data rate.

A

Access Point: Provides a bridge between Ethernet wired LANs and the wireless network. Access points are the connectivity point between

Ethernet wired networks and devices (laptops, hand-held computers, point-of-sale terminals) equipped with a wireless LAN adapter card.

Analog phone: Comes from the word "analogous," which means similar to. In telephone transmission, the signal being transmitted from the

phone — voice, video or image — is analogous to the original signal.

Antenna-Directional: Transmits and receives radio waves off the front of the antenna. The power behind and to the sides of the antenna is

reduced. The coverage area is oval with the antenna at one of the narrow ends. Typical directional antenna beam width angles are from 90°

(somewhat directional) to as little as 20°(very directional). A directional antenna directs power to concentrate the coverage pattern in a

particular direction. The antenna direction is specified by the angle of the coverage pattern called the beam width.

Antenna-Omni-directional: Transmits and receives radio waves in all directions. The coverage area is circular with the antenna at the center.Omni-directional antennas are also referred to as whip or low-profile antennas.

Association: The process of determining the viability of the wireless connection and establishing a wireless network's root and designated

access points. A mobile unit associates with its wireless network as soon as it is powered on or moves into range.

ATM: Asynchronous Transfer Mode. A type of high-speed wide area network.

GlossaryB




Backbone: A network that interconnects other networks, employing high-speed transmission paths and often spanning a large geographic

area.

Bandwidth: The range of frequencies, expressed in hertz (Hz), that can pass over a given transmission channel. The bandwidth determines

the rate at which information can be transmitted through the circuit.

Bandwidth Management: Functionality that allocates and manages RF traffic by preventing unwanted frames from being processed by the

access point.

BC/MC: Broadcast frames; Multicast frames

Beacon: A uniframe system packet broadcast by the AP to keep the network synchronized. A beacon Includes the Net_ID (ESSID), the AP

address, the Broadcast destination addresses, a time stamp, a DTIM (Delivery Traffic Indicator Maps) and the TIM (Traffic Indicator Message).

BFA Antenna Connector: Miniature coaxial antenna connector manufactured by MuRata Manufacturing Corporation.

Bluetooth: See Wireless Personal Area Networks.

Bridge: A device that connects two LANs of the same or dissimilar types. It operates at the Data Link Layer, as opposed to routers. The

bridge provides fast connection of two collocated LAN segments that appear as one logical network through the bridge.

Buffer: A segment of computer memory used to hold data while it is being processed.

GlossaryC

CAM: Continuously Aware Mode: Mode in which the adapter is instructed to continually check for network activity.




Card and Socket Services: Packages that work with the host computer operating system, enabling the Wireless LAN adapter to interface with

host computer configuration and power management functions.

Cellular Phone: Low-powered, duplex, radio/telephone that operates between 800 and 900 MHz, using multiple transceiver sites linked to acentral computer for coordination. The sites, or "cells," cover a range of one to six or more miles in each direction.

Centrex: Business telephone service offered by a local telephone company from a local telephone company office. Centrex is basically a single

line phone system leased to businesses as a substitute for a business that is buying or leasing its own on-premises phone system or PBX.

CDMA and TDMA: The Code Division Multiple Access and Time Division Multiple Access standard for wireless communications on wide

area networks (WANs) in North America.

Circuit switching: The process of setting up and keeping a circuit open between two or more users so that users have exclusive and full use of the circuit until the connection is released.

Client: A computer that accesses the resources of a server.

Client/Server: A network system design in which a processor or computer designated as a server (such as a file server or database server)

provides services to other client processors or computers.

CODEC: Coder-Decoder. Audio compression/decompression algorithm that is designed to offer excellent audio performance. Converts voice

signals from their analog form to digital signals acceptable to modern digital PBXs and digital transmission systems. It then converts thosedigital signals back to analog so that you may hear and understand what the other person is saying.

Computer Telephony Integration: Technology that integrates computer intelligence with making, receiving, and managing telephone calls.

Computer telephony integrates messaging, real-time connectivity, and transaction processing and information access.

GlossaryD




Data Terminal: Computer transmit and receive equipment, including a wide variety of dumb terminals or terminals without embedded

intelligence in the form of programmed logic. Most data terminals provide a user interface to a more capable host computer, such as a

mainframe or midrange computer.

Decryption: Decryption is the decoding and unscrambling of received encrypted data. The same device, host computer or front-end

processor, usually performs both encryption and decryption.

Desktop Conferencing: A telecommunications facility or service on a PC that permits callers from several diverse locations to be connected

together for a conference call.

Digital Phone System: Proprietary phone system provided by a vendor, such as AT&T, Mitel, Northern Telecom, and so on. The signal being

transmitted in a digital phone system is the same as the signal being transmitted in an analog phone system. The system can consist of a

proprietary PBX system that converts voice signals from their analog form to digital signals, and then converts those digital signals back toanalog. Alternatively, the conversion from analog-to-digital can occur in a digital phone.

Direct Inward Dialing: DID. The ability for a caller outside a company to call an internal extension without having to pass through an

operator or attendant. In large PBX systems, the dialed digits are passed from the PSTN to the PBX, which then completes the call.

Direct-Sequence (DS) Spread Spectrum: Direct sequence transmits data by generating a redundant bit pattern for each bit of information

sent. Commonly referred to as a "chip" or "chipping code," this bit pattern numbers 10 chips to one per bit of information. Compared with

frequency hopping, direct sequence has higher throughput, wider range and is upgradable in the 2.4GHz band.

Diversity Reception: The use of two antennas attached to a single access point to improve radio reception. The second antenna is used only

for receiving radio signals, while the primary is used for both transmitting and receiving.

Driver: A program routine that links a peripheral device, such as a mobile unit's radio card, to the computer system.

GlossaryElement-level Management: Level of technologies aimed at small or medium-sized businesses.

Encryption: Entails scrambling and coding information, typically with mathematical formulas called algorithms, before the information is transmitted over a network.

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Ethernet: A local area network used for connecting computers, printers, workstations, terminals, servers, and so on, within the same building or campus. Ethernet

operates over twisted wire and over coaxial cable at speeds up to 100 Mbps, with 1 Gbps speeds coming soon.

Filtering: Prevents user-defined frames from being processed by the access point.

Fragmentation Threshold: The maximum size for directed data packets transmitted over the radio. Larger frames fragment into several packets this size or smaller beforetransmission over the radio. The receiving station reassembles the transmitted fragments.

Frame Mode: A communications protocol supported by the OEM Modules. The frame protocol implements asynchronous serial Point-to-Point (PPP) frames similar to

those used by serial Internet protocols.

Frequency Hopping (FH) Spread Spectrum: Hedy Lamarr, the actress, is credited in name only for inventing frequency hopping during World War II. As its label

suggests, frequency hopping transmits using a narrowband carrier that changes frequency in a given pattern. There are 79 channels in a 2.4GHz ISM band, each channel

occupying 1MHz of bandwidth. A minimum hop rate of 2.5 hops per channel per second is required in the United States. Frequency hopping technology is recognized as

superior to direct sequence in terms of echo resistance, interference immunity, cost and ease-of-installation. To date, there has also been a greater selection of WLAN

products from which to chose.

FTP (File Transfer Protocol): A common Internet protocol used for transferring files from a server to the Internet user. It uses TCP/IP commands.

Gain, dBi: Antenna gain, expressed in decibels referenced to a half wave dipole.

Gain, dBi: Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator.

Gain, dBic: Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator that is circularly polarized.

Gatekeeper: Software that performs two important functions to maintain the robustness of the network: address translation and bandwidth management. Gatekeepers map

LAN aliases to IP addresses and provide address lookups when needed.

Gateway: Optional element in an H.323 conference. Gateways bridge H.323 conferences to other networks, communications protocols, and multimedia formats.

Gateways are not required if connections to other networks or non-H.323 compliant terminals are not needed.

GHz: International unit for measuring frequency is Hertz (Hz), which is equivalent to the older unit of cycles per second. One Gigahertz (GHz) is one billion Hertz.

Microwave ovens typically operate at 2.45 GHz.

GSM: The Global System for Mobile Communications standard for worldwide wireless communications on wide area networks (WANs).

GlossaryH.323: An umbrella standard from the International Telecommunications Union (ITU) that addresses call control, multimedia management, and bandwidth management

for point-to-point and multi-point conferences, as well as interfaces between LANs and other networks. The most popular standard currently in use.




Handheld PC (HPC): The term adopted by Microsoft and its supporters to describe handheld computers employing Microsoft's Windows CE operating system.

Interactive Voice Response: System used to access a database access application using a telephone. The voice processing acts as a front-end to appropriate databases that

reside on general purpose computers. For instance, DTMF (touch tone) input of a Personal Identification Number can be required for access or more unusual and

expensive techniques such as voice recognition and voice print matching.

Internet: World's largest network, often referred to as the Information Superhighway. The Internet is a virtual network based on packet switching technology. The

participants on the Internet and its topology change on a daily basis.

Internet Commerce: Electronic business transactions that occur over the Internet. Samples of Internet commerce applications include electronic banking, airline

reservation systems, and Internet malls.

Internet Phone: Device used to transmit voice over the Internet, bypassing the traditional PSTN and saving money in the process. An Internet phone can be a small phone

(such as the NetVision Phone) or a multimedia PC with a microphone, speaker, and modem.

Interoperability: The ability of equipment or software to operate properly in a mixed environment of hardware and software, from different vendors. Enabled by the

IEEE 802.11 open standard.

IP (Internet Protocol): The Internet standard protocol that defines the Internet datagram as the unit of information passed across the Internet. Provides the basis of the

Internet connection-less- best-effort packet delivery service. The Internet protocol suite is often referred to as TCP/IP because IP is one of the two fundamental protocols.

International Roaming: Ability to use one adapter worldwide.

Intranet: A private network that uses Internet software and Internet standards. In essence, an intranet is a private Internet reserved for use by people who have been given

the authority and passwords necessary to use that network.

ISDN: Integrated Services Digital Network. Emerging network technology offered by local phone companies that is designed for digital communications, computer

telephony, and voice processing systems.

ISM Band: ISM bands--instrumental (902-928MHz), science (2.4-2.4835GHz), and medical (5.725-5.850GHz)--are the radio frequency bands allocated by the FCC for

unlicensed continuous operations for up to 1W. The most recent band approved by the FCC for WLANs was the medical band in January 1997.

ITU: International Telecommunications Union. Standards body that defined H.323 and other international standards.

Jitter: Noise on a communications line which is based on phase hits, causing potential phase distortions and bit errors..

GlossaryKerberos: A widely deployed security protocol that was developed at the Massachusetts Institute of Technology (MIT) to authenticate users and clients in a wired

network environment and to securely distribute encryption keys.




Key Telephone System: A system in which the telephone has multiple buttons permitting the user to directly select central office phone lines and intercom lines. Key

phone systems are most often found in relatively small business environments, typically around 50 telephones.

Layer: A protocol that interacts with other protocols as part of an overall transmission system.

LPD (Line Printer Daemon): A TCP-based protocol typically used between a Unix server and a printer driver. Data is received from the network connection and sent out

over the serial port.

MAC (Media Access Control): Part of the Data Link Layer, as defined by the IEEE, this sublayer contains protocols for gaining orderly access to cable or wireless

media.

MD5 Encryption: An authentication methodology when MU is in foreign subnet.

MIB (Management Information Base): An SNMP structure that describes the specific device being monitored by the remote-monitoring program.

Microcell: A bounded physical space in which a number of wireless devices can communicate. Because it is possible to have overlapping cells as well as isolated cells,

the boundaries of the cell are established by some rule or convention.

Modem: Equipment that converts digital signals to analog signals and vice versa. Modems are used to send digital data signals over the analog PSTN.

MMCX Antenna Connector: Miniature coaxial antenna connector in use by several major wireless vendors.

Mobile IP: The ability of the mobile unit to communicate with the other host using only its home IP address, after changing its point of attachment to the Internet and

intranet.

Mobile Unit (MU): May be a Symbol Spectrum24 terminal, PC Card and PCI adapter, bar-code scanner, third-party device, and other

Mobile Unit Mode: In this mode, the WLAN adapter connects to an access point (AP) or another WLAN installed system, allowing the device to roam freely between

AP cells in the network. Mobile units appear as network nodes to other devices.

Modulation: Any of several techniques for combining user information with a transmitter's carrier signal.

Multipath: The signal variation caused when radio signals take multiple paths from transmitter to receiver.

Multipath Fading: A type of fading caused by signals taking different paths from the transmitter to the receiver and, consequently, interfering with each other.

Glossary Node: A network junction such as a switch or a routing center.

Packet Switching: Refers to sending data in packets through a network to some remote location. In a packet switched network, no circuit is left open on a dedicated basis.

Packet switching is a data switching technique only.




PBX Phone System: Private Branch eXchange. Small version of the phone company's larger central switching office. An alternative to a PBX is to subscribe to a local

telephone company's Centrex service.

PCMCIA (Personal Computer Memory Card International Association) PC Card: A credit card-size device used in laptop computers and available as removable network

adapters.

PCS (Personal Communications Service): A new, lower powered, higher-frequency competitive technology to cellular. Whereas cellular typically operates in the 800-

900 MHz range, PCS operates in the 1.5 to 1.8 GHz range. The idea with PCS is that the phone are cheaper, have less range, and are digital. The cells are smaller and

closer together, and airtime is cheaper.

Peer-to-peer Network: A network design in which each computer shares and uses devices on an equal basis.

Ping: A troubleshooting TCP/IP application that sends out a test message to a network device to measure the response time.

PLD (Data Link Protocol): A raw packet protocol based on the Ethernet frame format. All frames are sent to the wireless network verbatim--should be used with care asimproperly formatted data can go through with undesirable consequences.

Plug and Play: A feature that allows a computer to recognize the PCI adapter and configure the hardware interrupt, memory, and device recognition addresses; requires

less user interaction and minimizes hardware conflicts.

Pocket PC: The term adopted by Microsoft and its supporters to describe handheld computers employing Microsoft's Pocket PC operating system.

Point-of-Sale Device: A special type of equipment that is used to collect and store retail sales data. This device may be connected to a bar code reader and it may query a

central computer for the current price of that item.

POTS (Plain Old Telephone Service): The basic service supplying standard single line telephones, telephone lines, and access to the public switched telephone network.

Power Management: Algorithms that allow the adapter to sleep between checking for network activity, thus conserving power.

PSP (Power Save Polling): stations power off their radios for long periods. When a mobile unit in PSP mode associates with an access point, it notifies the AP of its

activity status. The AP responds by buffering packets received for the MU.

PSTN (Public Switched Telephone Network): Refers to the worldwide voice telephone network accessible to all those with telephones and access privileges. In the U.S.,

the PSTN is provided by AT&T.



Glossary




T1: A type of dedicated digital leased-line available from a public telephone provider with a capacity of 1.544 Mbps. A T1 line can normally handle 24 voice

conversations, each one digitized at 64 Kbps. With more advanced digital voice encoding techniques, it can handle more voice channels. T1 is the standard for digital

transmission in the U.S. Canada, Hong Kong, and Japan.

TCP/IP: Networking protocol that provides communication across interconnected networks, between computers with diverse hardware architectures, and variousoperating systems. TCP/IP is used in the industry to refer to the family of common Internet protocols.

TCP (Transport Communication Protocol): Controls the transfer of data from one client to one host, providing the mechanism for connection maintenance, flow control,

retries, and time-outs.

Telnet (Terminal Emulation Protocol): A protocol that uses the TCP/IP networking protocol as a reliable transport mechanism. Considered extremely stable.

Terminal: An endpoint, which provides for real-time, two-way communications with another terminal, gateway, or mobile unit.

Token Ring: A ring type of local area network (LAN) in which a supervisory frame, or token, must be received by an attached terminal or workstation before that

terminal or workstation can start transmitting. Token ring is the technique used by IBM and others.

UDP (User Datagram Protocol): UDP/IP is a connection-less protocol that describes how messages reach application programs running in the destination machine;

provides low overhead and fast response and is well suited for high-bandwidth applications.

Video Conferencing: Video and audio communication between two or more people via a video CODEC (coder/decoder) at either end and linked by digital circuits.

Voice Mail System: Device or system that records, stores, and retrieves voice messages. The two types of voice mail devices are those which are "stand alone" and those

which offer some integration with the user's phone system.

Wi-Fi: A logo granted as the "seal of interoperability" by the Wireless Ethernet Compatibility Alliance (WECA). Only select wireless networking products possess thischaracteristic of IEEE802.11b.

Wireless AP Support: Access Point functions as a bridge to connect two Ethernet LANs.

Glossary




Wireless Local Area Network (WLAN): A wireless LAN is a data communications system providing wireless peer-to-peer (PC-to-PC, PC-to-hub, or printer-to-hub) and

point-to-point (LAN-to-LAN) connectivity within a building or campus. In place of TP or coaxial wires or optical fiber as used in a conventional LAN, WLANs transmit

and receive data over electromagnetic waves. WLANs perform traditional network communications functions such as file transfer, peripheral sharing, e-mail, and

database access as well as augmenting wired LANs. WLANs must include NICs (adapters) and access points (in-building bridges), and for campus communications

building-to-building (LAN-LAN) bridges.

Wireless Personal Area Network (WPAN): Personal area networks are based on a global specification called Bluetooth which uses radio frequency to transmit voice and

data. Over a short range, this cable-replacement technology wirelessly and transparently synchronizes data across devices and creates access to networks and the Internet.

Bluetooth is ideal for mobile professionals who need to link notebook computers, mobile phones, PDAs, PIMs, and other hand-held devices to do business at home, onthe road, and in the office.

Wireless Wide Area Network (WWAN): Wide area networks utilize digital mobile phone systems to access data and information from any location in the range of a cell

tower connected to a data-enabled network. Using the mobile phone as a modem, a mobile computing device such as a notebook computer, PDA, or a device with a

stand-alone radio card, can receive and send information from a network, your corporate intranet, or the Internet.

A Few References




Berge J.,"Fieldbuses for Process Control: Engineering, Operation, Maintenance". ISA Press 2002, ISBN 1-55617-760-7.Black U., "Physical Level Interfaces and Protocols". IEEE, ISBN 0-8186-8824-6.Black U., "The V-series recommendations". McGraw-Hill, ISBN 0-07-005592-0.

Bonfig K., "Feldbus-Systeme". Expert Verlag 1992, 3-8169-0771-7.Borst W., "Der Feldbus in der Maschinen- und Anlagentechnik". Franzis Verlag, ISBN 3-7723-4621-9.British Standard Institute, "Guide to the evaluation of fieldbus protocols". Report DISC PD0014:2000.Brown, "The OSI Dictionary of acronyms". McGraw-Hill 1993, ISBN 0-07-057601-7.Burton, "Fieldbus for Industrial Control Systems". Chapmann & Hall 1997, ISBN 0-412-57890-5.Centrum voor Micro-elektronica, "Intelligente sensornetwerken". 1993, 1996Control Engineering, issues of 1994 and 1995, "Fieldbus series".Dietrich D., "Feldbustechnik in Forschung, Entwicklung und Anwendung". Springer Verlag, 1997.

ETG Fachbericht 37, "Datenübertragung auf Fahrzeugen mittels serieller Bussysteme". VDE Verlag, ISBN 3-8007-1829-4.ETZ Report 27, "Standardisierung der Prozeßdatenkommunikation". VDE Verlag 1991.Fachzeitschrift DE, "Bussysteme für die Gebäudeinstallation. Hüthig & Pflaum, 1999.Färber, "Bussysteme - parallele und serielle Bussysteme in Theorie und Praxis". Oldenbourg Verlag, ISBN 3-486-28581-5.Frankort, "Digitale Communicatie". Delta Press 1989, ISBN 90-6674-726-9.Gladdis, "How to automate your home". Baran-Harper 1991, ISBN 0-9632170-0-3.Gruhler, G. "Feldbusse und Geräte-Kommunikationssysteme". Franzis Verlag 2001, ISBN 3-7723-5745-8.Hill, "A distributed control & diagnostic architecture for railway maintenance". University of South-Carolina 1998.Holzmann, "Design and validation of computer protocols". Prentice-Hall, ISBN 0-13-539834-7.Huber J.,"Industrial Fiber Optic Networks". ISA Press 1995, ISBN 1-55617-521-3-G.Hulsebos, R., "Veldbussen". Kluwer 1996, ISBN 90-557-6059-5.IEE, "Colloquium: Fieldbus devices - A changing future". IEE 1994, Ref. 1994/236.ISA, "Fieldbus Standard for use in industrial control systems". ISA 1993, ISBN 1-55617-317-2.ISA, "The ISA Fieldbus Guide". ISA 1997, ISBN 1-55617-637-6.

Johannsmeyer, "Investigation into the intrinsic safety of fieldbus systems (FISCO)". PTB, report W53, ISBN 3-89429-310-1. Jordan, "Serial networked field instrumentation". Wiley 1995, ISBN 0-471-95236-1.



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