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`In 1985, the Federal Communications
`Commission (FCC) deregulated the spectrum
`from 2.4-2.5 GHz for use by the Industrial,
`
`Scientific, and Medical (ISM) communities.
`This meant that the spectrum would be
`available for
`individual,
` non-licensed
`applications [1]. This news was exciting to
`up-and-coming developers of wireless
`communications technologies, because they
`could now develop without spending money
`on licensing fees. Unfortunately, this led to
`many developments that were far from the
`ubiquitous, sprawling networks we see now.
`At the time, and throughout the development
`of the 802.11 standard, if wireless network
`technologies were available, they were
`usually proprietary, expensive, slow, or
`simply
`
`lacked
`
`widespread
`availability/adaptation – and most suffered
`from several of these challenges [2].
`In the early 1990s, however, the IEEE
`realized that a wireless communications
`infrastructure standard was necessary to meet
`a clearly-desirable market niche. The IEEE
`established an executive committee, as part
`of the IEEE 802 standard for Local and
`Metropolitan Area Networks to focus on
`developing a wireless LAN standard [2]. The
`802.11 committee focused on providing a
`reliable, fast, inexpensive, robust wireless
`
`1
`
`Page 1 of 33
`
`Samsung Exhibit 1034
`
`

`

`solution that could grow into a standard with
`widespread acceptance, using the deregulated
`ISM band from 2.4-2.5 GHz.
`The original standard, ultimately
`adopted in 1997, is vastly different from the
`standard that exists today. The maximum
`data rate was 2 Mbps. It included forward
`error correction, and two forms of
`interference mitigating spread spectrum
`methods – direct sequence and frequency
`hopping. It also included a specification for
`infrared wireless communications, still
`operating at up to 2 Mbps.
`A large part of 802.11's success is its
`inherent compatibility with current 802
`networks, specifically the 802.3 wired
`Ethernet networks [2]. The independence of
`physical access (PHY) and media access
`(MAC) from overlaying communication
`layers is critical to this compatibility. This
`compatibility was part of the 802.11
`committee's charter
`
`[1],
` but
`
`its
`implementation played a large role in
`ongoing internetwork growth.
`
` The
`compatibility was built on two pillars –
`physical layer compatibility and media access
`layer compatibility. The separation of these
`layers is critical to, not only the early
`implementation of the standard, but the
`ongoing extensibility of the standard.
`The physical layer portions of the
`original standard, and as well as today's
`standard, focus on allowing the base stations
`to get wireless broadcasts to one another;
`transceiving. The broadcast frequencies were
`in the 2.4 GHz to 2.483 GHz range or in the
`infrared spectrum (IR) (850-950 nm) [2].
`Transmitters used time-division duplex
`(TDD) radio broadcasts, allowing both uplink
`and downlink to share the same RF channel,
`using differential binary phase shift keying
`(DBPSK) or differential quadrature phase
`shift keying (DQPSK) signal modulation
`(Appendix A). Transmitters used either
`
`Direct Sequence Spread Spectrum (DSSS) or
`Frequency Hopping Spread Spectrum
`(FHSS) for interference mitigation. Data
`rates were specified for both 1 Mbps and 2
`Mbps operation.
`The media access layer (MAC)
`processes the PHY layer signals into the
`ubiquitous network layer. Fundamentally,
`802.11 uses collision sense media access with
`collision avoidance (CSMA/CA) for its
`media access protocol (Appendix B) [2]. The
`MAC layer also provides several services to
`assist in the wireless broadcast such as
`synchronization, power management, frame
`fragmentation, and frame encryption (WEP -
`Wired Equivalent
` Privacy)
`
`and
`authentication, with varying methods of
`employing
`these services for both
`infrastructure-based in distributed (known as
`ad-hoc) networks.
` For example, in an
`infrastructure network, synchronization is
`performed between all transceivers by using
`beacons transmitted by the access point. In
`an ad-hoc network,
` however,
`
`the
`synchronization responsibility falls to all
`members of the independent network,
`creating a sub-network of synchronizers.
`Note that there is no 5 GHz spectrum
`specification in the original 802.11-1997
`standard. This frequency allocation was not
`explored (or at least, published) until shortly
`after the original standard was adopted. The
`original standard focused on exploiting the
`recently-unlicensed 2.4 GHz ISM band, and
`the practical, and already-in-use infrared
`spectrum. In fact, the original standard
`largely overlooks, or at least actively ignores,
`many compatibility standards that would end
`up being crucial to widespread acceptance of
`the standard.
` For example, the entire
`standard makes only cursory mention of
`MAC address space, pointing out that its 48-
`bit address space is compatible within the
`broader scope of the IEEE 802 address space,
`
`2
`
`Page 2 of 33
`
`

`

`but is not required to be unique from a global
`802 address overlay. This compatible
`address space, which is still a part of the
`802.11 standard today, allows 802.11
`networks to interact with the 802.1 LAN
`specification that provides for bridging
`between separate physical networks, and is
`perhaps the cornerstone of the success for the
`standard. This address compatibility with
`802.x networks (and flexibility) played a role
`in
`the widespread adoption and
`interoperability of 802.11 wireless networks
`[2], even in the face of other, higher-speed
`competing network standards such as
`HiperLAN, a competing European standard
`for wireless network communications, which
`provided its own convergence to internet
`protocol (IP) networks, vice relying on 802.1
`for internetwork bridging [1].
`Despite not having addressed direct
`compatibility of the 802.11 with 802
`networks, the committee left the door open,
`and in fact immediately fostered the follow
`on Task Groups to address specific
`supplemental topics for use within the 802.11
`standard framework. The 802.11b task
`group, TGb, addressed higher speed
`transmissions
` within
`the
` WLAN
`environment. The 802.11b Task Group
`produced the 802.11b amendment, adopted
`by IEEE in 1999, just two years after the
`original standard was adopted. It allows for
`5.5 Mbps and 11 Mbps data rates, using
`Direct Sequence Spread Spectrum (DSSS)
`transmissions [2]. It also prompted the
`creation of
`the Wireless Ethernet
`Compatibility Alliance (WECA); a non-profit
`association for standardization and promotion
`of Wi-Fi technologies. From wi-fi.org [5]:
`“The Wi-Fi Alliance is a global non-profit
`industry association of hundreds of
`leading companies devoted to seamless
`connectivity.
` With
`
`technology
`
`3
`
` and
` market building,
`development,
`regulatory programs, the Wi-Fi Alliance
`has enabled widespread adoption of Wi-Fi
`worldwide.”
`
`Even today, 802.11b is probably the
`most widely-recognized, and widely-used
`802.11 standard, although 802.11g is quickly
`surpassing it, with 802.11n up-and-coming in
`popularity and availability. WECA renamed
`itself to the Wi-Fi Alliance in October, 2002
`[4].
`About the same time the 802.11b
`Task Group was designing the 802.11b
`amendment, the 802.11a Task Group, TGa,
`was doing the same for another wireless
`standard [3]. At the time, many countries
`had recently opened up some 5 GHz
`spectrum for unlicensed (but still regulated)
`use. This spectrum was less “RF dense” than
`the 2.4 GHz spectrum [2], which includes
`other interferors such as garage door openers,
`cordless telephones, microwave ovens, and
`baby monitors. With less interference high
`bandwidth available, another, higher capacity
`standard could be constructed.
`The ultimate 802.11a standard
`included a 54 Mbps data rate using the more-
`complex orthogonal frequency division
`multiplexing (OFDM) waveforms (Appendix
`C), and operated in the 5 GHz range, set
`aside for
`the Unlicensed National
`Information Infrastructure (U-NII) usage [1].
`While the standard was completed and
`adopted in 1999,
` the more-complex
`equipment did not begin shipping until 2001.
`It is significant to note that while data
`rates were increased by both 802.11a and
`802.11b, that both only increased data
`bandwidth within RF applications. The IR
`specification, while still valid, was left
`behind with 1-2 Mbps maximum throughput,
`while the RF environment has continued to
`
`Page 3 of 33
`
`

`

`increase in data throughput throughout the
`development of the 802.11 standard.
`Not long after 802.11a was adopted,
`IEEE immediately recognized that the
`OFDM waveform could benefit the 802.11b
`standard. Increased data rates would even
`support
` bandwidth-hungry multimedia
`applications as the demand for these
`applications grew. In July 2000, the 802.11
`Task Force G was assigned the task of
`overlaying the OFDM waveform on the 2.4
`GHz spectrum, producing a new standard that
`was fully backward-compatible with the
`802.11b standard. This was no easy feat, but
`after 3 years the new standard was ratified.
`The key was in requiring all 802.11g
`equipment to support complimentary code
`key (CCK) modulation as a fall-back
`mechanism to ensure 802.11b compatibility.
`This fall-back has significant impacts on the
`total data rate of the network, but allows
`mixed 802.11b-802.11g network equipment
`to coexist on the same topology. As 802.11b
`equipment is phased out and replaced with
`802.11g equipment, users can seamlessly
`upgrade their network without upgrading the
`entire infrastructure. In June 2003, the
`amendment was ratified.
`As 802.11 enjoyed widespread
`adoption by home and business users alike,
`more scrutiny was placed on security. The
`initial standard included a MAC-level
`security protocol called WEP, Wired
`Equivalent Privacy [6]. WEP was intended
`to provide confidentiality and authentication
`for connecting users. By using a very small
`subset (up to four) of pre-shared keys, a user
`could identify itself as a valid user to an
`access point, and encrypt every packet of the
`session [7]. The intent of WEP was not to be
`a bulletproof security protocol for wireless
`networks, but to provide reasonable session
`privacy, like that which could be expected
`from a direct-connection (wired) connection.
`
` WEP was rife with
`Unfortunately,
`vulnerabilities (Appendix D), and continued
`bad press caused 802.11 users to demand
`better security [7]. Another task group, Task
`Group I, was set up to address MAC-level
`security in an effort to address security
`problems with WEP [6].
`The Task Group model, however,
`took too long to address the concerns of
`equipment manufacturers.
` The Wi-Fi
`Alliance began implementing additional
`security enhancements to provide customers
`with additional security features. Many
`members of the Wi-Fi Alliance were part of
`Task Group I, and these enhancements would
`be seen as part of the final 802.11i
`amendment.
` These original security
`implementations, labeled Wireless Protected
`Access included many enhancements to
`address the weaknesses of WEP, including
`the use of extended initialization vectors (IV)
`(56-bits), rotating initialization vectors, more
`robust integrity checks, and protection
`against replay/redirection attacks [6].
`In June 2004, the 802.11i amendment
`was ratified. The security enhancements in it
`became known as WPA2, Wireless Protected
`Access v2. It was largely a mirror of the
`WPA enhancements from the Wi-Fi Alliance,
`with some small,
` but
` significant,
`improvements. First, it incorporated the use
`of the Advanced Encryption Standard for
`encrypting and protecting data [8]. The AES
`was selected/adopted by the National
`Institute of Standards and Technology
`(NIST) in November 2001, and was not
`available when WEP was being designed
`nearly 10 years earlier. Next, enhanced
`integrity checks leveraging the AES CCMP
`(counter mode with cipher block chaining
`with message authentication code protocol, a
`recursive acronym) provides additional
`authentication. 802.11i also supports several
`implementations
` of
` using external
`
`4
`
`Page 4 of 33
`
`

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`The 802.11 standard, while a single standard,
`has many manifestations that allow wireless
`network access. It covers everything from
`how synchronization should be performed, to
`how infrared (IR) wireless networks should
`be configured, to spread spectrum chip rates
`for different applications. This paper cannot
`touch on all portions of the standard. Indeed,
`the 1200+ page standard (not including its
`many
`
`several-hundred
`
`page
`amendments/enhancements) will require this
`paper leave many topics unexplored, and
`many, many more topics completely
`undiscovered.
`
`authentication mechanisms, including 802.1X
`authentications and/or RADIUS [8].
`Meanwhile, the IEEE was going
`through another exercise to increase wireless
`data rates. Recognizing the seemingly
`unquenchable bandwidth thirst of users, the
`IEEE set out to exceed 54 Mbps as an upper
`data rate limit by creating Task Group n
`(TGn) in September 2003 [3]. By using
`multiple-input
` multiple-output
` (MIMO)
`transmitting methods, 802.11n would allow
`multiple data streams, separated spatially, to
`increase the overall data rate [9]. This access
`method, as with 802.11g, is backward-
`compatible with previous 2.4 GHz
`implementations of 802.11, as well as
`802.11a in the 5 GHz and 3.7 GHz spectra
`(802.11a was extended to 3.7 GHz by the
`802.11y amendment in Nov 2008) [9].
`While 2.4 GHz implementations
`include the largest number of users
`worldwide, unfortunately the 2.4 GHz
`spectrum is heavy on interference. While
`MIMO can provide additional and higher
`data rates, and protection against some
`interferences (Appendix E), there is a limit as
`to how much data can be transferred in the
`congested spectrum.
`
` The 802.11n
`amendment, ratified in September 2009, can
`support data rates up to 600 Mbps, but in its
`current implementation, with the congestion
`in the 2.4 GHz spectrum, the maximum
`supported transmission rate is 104 Mbps.
`This is still a significant increase over the
`802.11g amendment, but leaves significant
`room for growth, should 802.11n be
`deployed in other RF environments. Indeed,
`as the amendment does not specify the exact
`spectrum, the largest performance gains will
`be realized in the 5 GHz and 3.7 GHz ranges,
`where significantly less interference is found.
`'
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`Page 5 of 33
`
`

`

`Evolution Timeline of 802.11 Standards
`
`1990
`
`1992
`
`1994
`
`1996
`
`1998
`
`2000
`
`2002
`
`2004
`
`Year Z|
`
`2006
`
`2008
`
`2010
`
`Terminated
`2012
`
`Initiated
`
`Ratified
`
`Core Standard
`
`IEEE Milestone
`
`802.11
`-¥- 802.11a
`-¥ 802.11b
`4 802.11¢
`> 802.11d
`+ 802.11e
`++ 802.11F
`
`-¥ 802.119
`- 802.11h
`> 802.11i
`
`+ 802.14)
`+ 802.11k
`-© 802.11n
`
`-4- 802.11
`+ 802.11r
`++ 802.115
`& 802.11u
`- 802.11v
`4 802.11w
`
`- 802.1 1y
`E 802.11z
`
`Page 6 of 33
`
` 

  
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`6
`
`Page 6 of 33
`
`

`

`
`" 
`802.11 networks can operate in two basic
`modes: infrastructure and ad-hoc[2].
`Infrastructure:
` In infrastructure
`networks there are two entities: a station
`(STA) and an access point (AP). This mode
`is called the Infrastructure Basic Service Set,
`or just BSS. Access points provide wireless
`access to network resources for stations, as
`well
` as other services such as
`synchronization and channel selection. Many
`times, APs are gateways, and provide other
`services such as network address translation,
`dynamic host control protocol (DHCP), and
`other network services. While these services
`are outside the bounds of 802.11, they are
`critical to end-to-end usability of the network
`[2].
`
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`Since the IEEE has continued to provide
`backward-compatible amendments to the
`original standard, all the 2.4 GHz methods
`used by 802.11 for RF transmission are still
`valid [2]. That is, since no amendment
`nullifies a previous access method, all the
`
`Page 7 of 33
`
`

`

`previous methods are still legitimate
`waveforms and spread spectrum techniques.
`For a discussion of RF waveforms, see
`Appendices.
`
`Channel Number
`
`Japan
`
`Regulatory Body (Region)
`FCC
`IC
`ETSI
`(Canada)
`(Europe)
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`X
`
`Frequenc
`y (GHz)
`1
`2.412
`X
`2
`2.417
`X
`3
`2.422
`X
`4
`2.427
`X
`5
`2.432
`X
`6
`2.437
`X
`7
`2.442
`X
`8
`2.447
`X
`9
`2.452
`X
`10
`2.457
`X
`11
`2.462
`X
`12
`2.467
`X
`13
`2.472
`X
`14
`2.484
`X
`Table 1: 24. GHz Channel Allocations by
`Region ([reproduction, 12]
`
`802.11 – Allows for frequency
`hopping spread spectrum (FHSS) and direct
`sequence spread spectrum (DSSS) to provide
`interference mitigation and binary phase shift
`keying (BPSK) or quadrature phase shift
`keying (QPSK) to provide 1 or 2 Mbps data
`rates, respectively.
` Since all future
`amendments would be backward-compatible,
`all future methods support these access rates
`[9].
`
`802.11b – Uses Direct Sequence
`Spread Spectrum (DSSS) with overlapping
`channels to provide interference mitigation,
`and moves away from FHSS for higher data
`rates. 802.11b also uses Differential QPSK
`(DQPSK) or Differential BPSK (DBPSK) to
`provide 11 Mbps or 5.5 Mbps data rates,
`respectively [2].
`
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`Data Rate (Mbps)
`54
`48
`36
`24
`18
`12
`11
`9
`6
`5.5
`2
`1
`
`Transmission Type
`OFDM
`OFDM
`OFDM
`OFDM
`OFDM
`OFDM
`DSSS
`OFDM
`OFDM
`DSSS
`DSSS
`DSSS
`
`Modulation Scheme
`64 QAM
`64 QAM
`16 QAM
`16 QAM
`QPSK1
`QPSK
`CCK2
`BPSK3
`BPSK
`CCK
`QPSK
`BPSK
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`standard includes mechanisms to allow
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`40 MHz channel usage is practical, allowing
`maximum throughput when feasible, but
`being able to step down to 20 MHz channel
`allocation when necessary. In many ways,
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`9
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`this is just flow control for frequency division
`multiplexing. This method protects legacy
`802.11b/g networks, as well as other 2.4 GHz
`transmitters, like Bluetooth [16].
`Another method is for the 802.11n
`station to announce on both 20 MHz channel
`allocations that all legacy (non-high
`throughput) network equipment should leave
`the channel open for some period of time,
`and then broadcast at the full data rate on
`both 20 MHz channels (providing 40 MHz
`channel allocation) for the specified period of
`time [16].
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`Page 9 of 33
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`802.11a – A 5 GHz operating frequency
`allowing communication up to 54 Mbps
`using an OFDM waveform [2].
` This
`standard, with its high bandwidth, operating
`in the reasonably unused 5 GHz frequency
`band was expected to be the workhorse for
`business and office applications. While it did
`find some success in this arena, its high
`operating frequency was readily absorbed by
`physical impediments such as walls, floors,
`and ceilings, significantly decreasing its
`effective range. Also, the increase in the
`inexpensive 802.11b hardware made it
`difficult to justify the the purchase and
`support of the more expensive 802.11a
`equipment. Many applications opted for the
`802.11b (see below) standard , with lower
`bandwidth, cheaper hardware costs, and
`typically further operating ranges.
`802.11b – A 2.4 GHz operating frequency
`(unlicensed ISM), communicating up to 11
`Mbps using a Complimentary Code Keying
`(CCK) broadcast.
` This standard was
`expected to be adopted by private individuals
`and small operating environments due to its
`inexpensive production costs and relatively
`convenient
`
`configuration
`
`options.
`
`Unfortunately, the unlicensed ISM band at
`2.4 GHz is a “crowded” spectrum, and there
`are plenty of interference producing products
`on the market, to include microwaves,
`portable phones (now, almost completely
`digital, and nearly defunct), and Bluetooth
`headsets.
`802.11c – Network bridging procedures for
`compatibility with other 802 networks
`(specifically 802.1d).
`802.11d – Compatibility and conformance
`extensions for transmitter operation outside
`of the typical political subdivisions of the
`802.11 standard.
` This effectively is a
`standard that allows a transmitter to roam
`between regions
`that
` observe/enforce
`different effective spectra for 802.11
`transmitters [17].
`802.11e – Quality of Service (QoS) functions
`for multi-application support. With these
`extensions, 802.11 is able to support many
`delay-sensitive applications which might
`otherwise suffer adverse effects of not having
`QoS, such as real-time video or voice over IP
`(VoIP) [3].
`802.11f – Inter-Access Point protocol used
`for managing the handoff of a user between
`access points in an 802.11 network. This
`specification was withdrawn in Feb 2006 [3].
`802.11g – A 2.4 GHz operating frequency
`(unlicensed ISM) , communication up to 54
`Mbps using a OFMD broadcast, and fully
`backward-compatible with 802.11b. This
`specification allows a significant increase in
`network throughput for the 2.4 GHz range,
`and when coupled with its backward-
`compatible feature and inexpensive hardware
`has lead to a global adoption as the de-facto
`preferred wireless network standard for
`
`10
`
`Page 10 of 33
`
`

`

`“typical” computer applications [14].
`802.11h – Extensions to the 5GHz broadcast
`of 802.11a that address mitigating issues
`from interference on the 5 GHz spectrum
`from other applications such as radar and
`satellite broadcasts, including power control
`and dynamic frequency selection [18].
`802.11i – Security enhancements (WPA2) to
`address the shortcomings of previous security
`protocols (WEP). This standard includes
`support for robust encryption by including
`the AES, and more robust authentication [6].
`802.11j – Broadcast standard to allow 802.11
`to be formalized in Japan, where broadcast
`requirements only allow 802.11 to operate in
`the 4.5-5 GHz spectrum [19].
`802.11k – Radio resource measurement for
`802.11 networks, allowing mobile stations to
`dynamically identify which access points
`(APs) within range will provide the best
`network performance, based on more than
`simply received signal strength, but on a
`complete report from each AP of its current
`network utilization, availability and received
`signal strength [20].
`802.11n – The incorporation of multiple
`input multiple output (MIMO) and increased
`bandwidth channels to the current broadcast
`sets (802.11g and 802.11a), increasing the
`total data throughput [9]. Contrary to current
`marketing, 802.11n is not a replacement to
`the 802.11g standard, but is a complementary
`performance increase that allows the use of
`multiple (usually two for current commercial
`availability) 802.11g broadcasts to share the
`same spectrum, thus increasing (doubling in
`the case of two data streams) the effective
`802.11g data throughput [15]. The same
`technique can be applied to 802.11a in the 5
`
`GHz spectrum. The current 802.11n standard
`is designed to support up to 600 Mbps
`throughput [15].
`802.11p – Extensions for vehicular (fast-
`moving) 802.11 access and handoffs, called
`Wireless Access for
`the V