Cost Benefit Issues in Wireless

1

• Cost Benefit Issues in Wireless
• Local Area Network (WLAN) Implementation
• Presented to
• The Society of Cost Estimating and Analysis
• National Conference and Training Workshop
• June 11-14, 2002
• Scottsdale, Arizona
• Stephen Gross
• The MITRE Corporation
• Economic Decision Analysis Center
• Email sgross_at_mitre.org

MITRE
2
Agenda

• Introduction
• Objective
• Background
• How WLANS Work
• WLAN Technology Option
• Customer Design Issues
• User Benefits
• Enterprise Benefits
• Security Issues
• Cost Consideration
• Typical ROI
• Summary
• References
• WLAN Glossary

3
Introduction

• A fundamental challenge facing information
  technology (IT) decision makers is identifying
  and implementing architectures, technologies, and
  processes that reduce the total cost of ownership
  (TCO) of corporate networks - one way is the
  wireless LAN (WLAN).
• WLAN is not a replacement for the wired
  infrastructure, but it is a significant
  complement to it. Schools, manufacturing
  companies, hospitals, and government offices
  purchase WLAN systems for two predominant
  reasons increase in user and IT team
  productivity.
• WLANs consist of Network Interface Cards (NICs)
  and access points/bridges (end-user-to-LAN and
  LAN-to-LAN) for communications. NICs provide an
  interface between the end-user device (desktop
  PC, portable PC, or handheld computing device)
  and the airwaves via an antenna on the access
  point/bridge.

4
Objectives

• To obtain a more thorough understanding of how
  wireless LANs are being implemented,
  corroborating and enhancing previous qualitative
  research conducted by several leading technology
  corporations
• To provide in-depth insight into the costs and
  benefits of wireless LAN implementation, as well
  as offering input into the challenges experienced
  by organizations who have deployed wireless LANs
• To show how cost savings and/or benefit
  associated with the deployment of wireless LAN
  technologies can be obtained and presented for
  organizations aspiring to justify expenditure for
  the deployment of wireless LANs

5
Background

• Wireless Networking is an exciting technology
  that enables computer users to access files
  stored on a network while moving around or
  working in a temporary office spaceor enable one
  to access a network in other locations
• A variety of applications have benefited from the
  WLAN implementation. Among these are
• Home Usage - Wireless networks can save time and
  money
• Small business - entrepreneurs focus on growing
  their businesses and WLAN can grow with them
  Enterprise - Many larger corporations and
  manufacturing facilities found that significant
  benefits of their WLANs. In most instances, only
  a portion of the network is wireless
• LAN to LAN Bridging - Installing buried cable
  between buildings to provide connectivity may be
  difficult at times, but with wireless many
  companies are finding a quick and reliable
  solution.

6
How WLANs Work

• Wireless LANs use electromagnetic airwaves (radio
  and infrared) to communicate information from one
  point to another without relying on any physical
  connection.
• In a typical WLAN configuration, a
  transmitter/receiver transceiver) device, called
  an access point, connects to the wired network
  from a fixed location using standard Ethernet
  cable.
• At a minimum, the access point receives, buffers,
  and transmits data between the WLAN and the wired
  network infrastructure. A single access point
  can support a small group of users and can
  function within a range of less than one hundred
  to several hundred feet.
• End users access the WLAN through wireless LAN
  adapters, which are implemented as PC cards in
  note-book computers, or use ISA or PCI adapters
  in desktop computers, or fully integrated devices
  within hand-held computers. WLAN adapters provide
  an interface between the client network operating
  system (NOS) and the airwaves (via an antenna).
  The wireless connection is transparent to the
  NOS.

7
WLAN Cells Attached to a Wired Network
8
WLAN Technology Options

• Most wireless LAN systems use spread-spectrum
  technology, a wideband radio frequency technique
  originally developed by the military for use in
  reliable, secure, mission-critical communications
  systems.
• Spread-spectrum is designed to trade off
  bandwidth efficiency for reliability, integrity,
  and security. There are two types of spread
  spectrum radio frequency hopping and direct
  sequence.
• A narrowband technology -- radio system transmits
  and receives user information on a specific radio
  frequency. Narrowband radio keeps the radio
  signal frequency as narrow as possible just to
  pass the information. Undesirable cross talk
  between communications channels is avoided by
  carefully coordinating different users on
  different channel frequencies.

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Customer Design Issues

• THROUGHPUT -- Factors that affect throughput
  include airwave congestion (number of users),
  range, the type of WLAN system used, as well as
  bottlenecks on the wired portions of the WLAN.
  Typical data rates range from (1 to 11 Mbps).
• COVERAGE -- Function of product design including
  transmitted power and receiver design and the
  propagation path, especially in indoor
  environments. Coverage for typical WLAN systems
  varies from under 100 feet to more than 500 feet.
  
• INTEROPERABILITY -- Industry-standard
  interconnection with wired systems, including
  Ethernet (802.3) and Token Ring (802.5).
  Wireless LAN nodes are supported by network
  operating systems in the same way as any other
  LAN node-via drivers.
• RELIABILITY -- Wireless data technologies have
  been proven in both commercial and military
  systems. While radio interference can cause
  degradation in throughput, such interference is
  rare. WLANs provide data integrity performance
  equal to or better than wired networking.

10
User Benefits

• The three primary reasons for the deployment of
  wireless network access mirror the top benefits
  to both companies and employees
• Mobility/ Not tied to a location
• Elimination of cabling/ wiring and associated
  costs
• Provide employees with access to e-mail/ servers
  when away from office

Based on Survey Data conducted See Reference 2
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Enterprise Benefits

• Companies consider cabling and its associated
  costs to be the primary benefit of WLAN
• A second widely cited benefit is increased
  mobility and information access followed by gains
  in productivity.

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Security Issues

• Many WLAN devices today do not have adequate
  security. The optional 40-bit RC4 ciphers in the
  original IEEE WLAN standard has been shown to be
  breakable.
• Ciphers implemented in software are not
  certifiable (by the DIA and the NSA) as
  militarily secure.
• Most ciphers today encrypt the data, they do not
  encrypt the headers

ORiNOCO, which is a subsidiary of Lucent
Technologies (now called Avaya Corporation).
Their Gold PC Card can use a 128-bit RC4
cipher, which is considered essentially
unbreakable.
The RC4 40-bit cipher can be broken in just a
few seconds working with an expensive machine.
(RSA Burt Kalinski 6/22/2002)
13
Selected Major WLAN Manufacturers
As of Dec. 2001. Figures represent vendor
published quotes and may not correspond to
individual situations
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Costs Considerations

• Cost Element Structure (CES) for WLAN
  Implementation
• Investment
• Network Interface Cards
• Access Points
• WLAN Management SW
• Test and Evaluation Costs
• OS
• User Training
• IT training
• License Fees (HW SW)
• Infrastructure maintenance

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Typical WLAN ROIs
 

• ROI (Present Value of Net Savings) / (Present
  Value of Net Investments)
• On an annualized basis, the ROI is that
  discount rate at which the present value of the
  savings is equal to the present value of the
  investment cost through the life cycle of the
  project being evaluated.

   
Based on data published by the WLAN Association
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Best Practices for Deploying WLANS

• Multi-Site Consistency -- IT staff need to ensure
  WLAN setup, settings and configurations are
  similar and thus transparent to the worker and
  remain consistent throughout offices
• users will be able to seamlessly connect to
  enterprise-wide resources with little to no
  re-configuration
• mobile workers experience less down time
• IT staff will be relieved of technical support
  requirements
• APs and Client Management -- partner with a
  company that can support the entire wireless
  infrastructure, including services such as a 24/7
  help desk, remote administration capabilities and
  RF diagnostics
• Wireless Card Interoperability -- 802.11b cards
  from various vendors can provide very different
  range limits. This is the result of the basic
  radio frequency (RF) performance of the radios
  transmitter/receiver.

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Best Practices for Deploying WLANS - concluded

• Security 802.11 based products have experienced
  a great deal of criticism due to their
  vulnerabilities security features may not be
  interoperable among various vendors. Security
  solutions differ depending on control over client
  card deployment.
• Site Survey (SS) SS can provide details about
  coverage and bandwidth performance at different
  locations
• Indicates where access points should be located
• Access point density will increase if an all
  time 11Mbps coverage area is required
• Clearly indicate where the fall back data rate of
  5.5, 2 and 1Mbps areas are
• Antenna Selection select antenna for
  flexibility and robustness to optimize your
  applications

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Summary

• Wireless LANs should be a high growth market over
  the next five years, both in terms of new
  customers and deeper penetration.
• Adopters have realized, and Intenders recognize,
  important benefits/advantages at both the
  corporate and employee levels.
• Security has been, and remains, the overriding
  concern regarding wireless networking
  deployments.
• VPN functionality/support ranks second behind
  802.1x in relative importance to Organizational
  adopters and intended users.

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References

• Wireless LAN ROI/Cost-Benefit Study, Sponsored by
  The Wireless LAN Association, October 1998
• Wireless LAN Benefit Study, NOP Worldwide, Fall
  2001, Conducted on Behalf of CISCO Systems, Inc.
• Bing, Benny, 2000, High-Speed Wireless ATM and
  LANs, Artech House Publishers.
• Van Nee, Richard, Geert Awater, Masahiro
  Morikura, Hitoshi Takanashi, Mark Webster, and
  Karen Halford, December 1999, New High-Rate
  Wireless LAN Standards, IEEE Communications
  Magazine, pp. 82-88.
• Bugala,, Paul, April 2001, Wireless LANs
  Management Forecast and Analysis, IDC.
• IEEE 802.11-1997, November 18, 1997, Information
  TechnologyTelecommunications and Information
  Exchange between Systems, Local and Metropolitan
  Area Networks, Specific RequirementsPart 11
  Wireless LAN Medium Access Control (MAC) and
  Physical Layer (PHY) Specifications.
• IEEE 802.11a b-1999, January 20, 2000,
  Supplement to IEEE Standard for Information
  TechnologyTelecommunications and Information
  Exchange between Systems, Local and Metropolitan
  Area Networks, Specific RequirementsPart 11
  Wireless LAN Medium Access Control (MAC) and
  Physical Layer (PHY) Specifications, High-Speed
  Physical Layer in the 5-GHz Band.

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W20LAN Glossary
Access Point A device that transports data
between a wireless network and a wired network
(infrastructure). IEEE 802.X A set of
specifications for Local Area Networks (LAN) from
The Institute of Electrical and Electronic
Engineers (IEEE). Most wired networks conform to
802.3, the specification for Ethernet networks.
The 802.11 committee completed a standard for 1
and 2 Mbps wireless LANs in 1997 that has a
single MAC layer for the following physical-layer
technologies Frequency Hopping Spread Spectrum,
Direct Sequence Spread Spectrum, and Infrared.
IEEE 802.11 HR, an 11 Mbps version of the
standard. Independent network A network that
provides (usually temporarily) peer-to-peer
connectivity without relying on a complete
network infrastructure. Infrastructure network
A wireless network centered around an access
point. In this environment, the access point not
only pro-vides communication with the wired
network but also mediates wireless network
traffic in the immediate neighborhood. Microcell
A bounded physical space in which a number of
wireless devices can communicate. Because it is
possible to have overlap-ping cells as well as
isolated cells, the boundaries of the cell are
established by some rule or convention. Roaming
Movement of a wireless node between two
microcells. Roaming usually occurs in
infrastructure networks built around multiple
access points. Wireless Node A user computer
with a wireless network interface card (adapter).