Saint Petersburg State University of Telecommunications Roman V. Plyaskin Advisor: Prof. Alexander E. Ryzhkov

Outline Review of Wi-Fi networks IEEE standard QoS in Wi-Fi networks A Wi-Fi network model

MuseumsHospitalsConferences Review of Wi-Fi networks

Hotspots AirportsHotelsCafes

Russian operators AeroportPeter-star AistPolyarnaya Zvezda ArtCommunicationsQuantum AvantelRambler Telecom CityNetRinet Comstar United TelesystemsRISS Telecom EquantRTComm-Yug eWi-FiSamara Internet Golden TelecomSouth Telecommunications Company Infotecs Taganrog TelecomStelcom MegaFonTascom MoscomVimpelcom MTSWi-Finder MTU-Intel**Wiland Netprovodov.ruZebra Telecom Source: J'son & Partners

Top Russian Wi-Fi providers RankCompanyCityHotspots 1.TascomMoscow40 2.QuantumSt. Petersburg22 3.MoscomMoscow20 4.StelcomMoscow17 5.Golden Telecom Moscow15 6.PeterstarSt. Petersburg11 7.EWi-FiMoscow10 Source: J'son & Partners

Two models of Wi-Fi services providing CommercialNoncommercial 3-15 $ per hour or MB of the traffic Cost of one-time installation and monthly subscription fees

Top Wi-Fi providers by commercial and free-of-charge locations RankCompanyCityCommercial Free-of- charge * Test 1.TascomMoscow QuantumSt. Petersburg22-n/a 3.MoscomMoscow StelcomMoscow Golden Telecom Moscow PeterstarSt. Petersburg EWi-FiMoscow10-n/a Sources: Company Data, J'son & Partners

Source: J'son & Partners

Number of hotspots Source: J'son & Partners

Share of noncommercial hotspots Source: J'son & Partners

According to J’son & Partners, there will be 1250 – 1500 commercial hotspots and thousands Wi-Fi users by the end of 2008 According to BroadGroup agency, which has analyzed the fees of 122 operators in 28 countries, the average European fee is € 5,74 per hour (without taxes). Since the beginning of 2004 it has been decreased in 11%.

The scope of the standard is to develop a medium access control and physical layer specifications for providing quick wireless connectivity between portable and moving stations within a local area. IEEE standard

BSS1 BSS2 STA1 AP STA3 STA2 infrastructure network DS ESS

BSS1 BSS2 STA1 STA2 STA3 STA4 STA5 Ad hoc network

Frequency Hopping Spread Spectrum - FHSS different frequency hopping schemes Direct Sequence Spread Spectrum - DSSS spread by Barker code

802.11b wireless networks Data rate, MbpsCode sequenceModulation 111 chips (Barker code)DBPSK 211 chips (Barker code)DQPSK 5,58 chips (СCK)DQPSK 118 chips (СCK)DQPSK

802.11g wireless networks Data rates, MbpsModulation ObligatoryOptional 1Barker code 2 5,5CCKРВСС 6ERP-OFDMDSSS-OFDM 9ERP-OFDM, DSSS-OFDM 11CCKРВСС 12ERP-OFDMDSSS-OFDM 18ERP-OFDM, DSSS-OFDM 22РВСС 24ERP-OFDMDSSS-OFDM 33РВСС 36ERP-OFDM, DSSS-OFDM 48ERP-OFDM, DSSS-OFDM 54ERP-OFDM, DSSS-OFDM

voice over Internet Protocol (VoIP) video streaming music streaming interactive gaming Quality of Service in Wi-Fi networks QoS allows network owners to leverage the Wi-Fi infrastructure to offer a richer set of services.

Wi-Fi home networking is spreading rapidly among households Residential broadband penetration has taken off New services, digital content, and new applications are becoming more widely available A wide range of products addressing digital entertainment connectivity are rapidly entering the market Demand for Wi-Fi multimedia applications is growing rapidly due to:

Enterprise market cost savings prioritized traffic management Public market Users are increasingly accustomed to VoIP and multimedia applications. Residential market a wider array of Wi-Fi-enabled devices providing wireless voice connectivity using the Wi-Fi network to distribute content from a media server establishing wireless connectivity between devices supporting peer-to-peer networks for telephony or gaming

Access CategoryDescription802.1D tags VoiceHighest priority. Allows multiple concurrent VoIP calls, with low latency and toll voice quality 7, 6 VideoPrioritize video traffic above other data traffic. One g or a channel can support 3-4 SDTV streams or 1 HDTV streams 5, 4 Best EffortTraffic from legacy devices, or traffic from applications or devices that lack QoS capabilities. Traffic less sensitive to latency, but affected by long delays, such as Internet surfing 0, 3 BackgroundLow priority traffic (file downloads, print jobs) that does not have strict latency and throughput requirements 2, 1 Access categories

A Wi-Fi network model Access Point Station 1 MPEG-4 Stations downloading files from the Internet

Superframe Contention free period (CFP) Contention period (CP) Beacon TXOP STA 1 ACK framesBeaconCF - End Data Frames Station 1 (MPEG-4) Other stations (Internet data) t

Contention free period (CFP) TXOP STA 1 Station 1 (MPEG-4) Other stations (data) Contention free period (CFP) TXOP STA 1 STA 2 STA 3 STA 4 STA 5 STA 6 STA 2 STA 3 STA 4 STA 5 STA 6 STA 7 STA 8 t t

Scenario 1. Throughput

Scenario 1. Delays

Station 1 (MPEG-4) Other stations (data) Contention free period (CFP) TXOP STA 1 STA 2 STA 3 STA 4 STA 5 t TXOP STA 1 STA 2 STA 3 t Contention free period (CFP)

Scenario 2. Throughput

Scenario 2. Delays

Scenario 3. Throughput

Scenario 3. Delays

Scenario 4. Throughput

Scenario 4. Delay

Scenario 4. Throughput

Scenario 4. Delays

Scenario 5. Throughput

Scenario 5. Delays

Conclusion Tendency of Wi-Fi networks spreading in Russia Importance of QoS implementation in Wi-Fi networks simulation of a typical Wi-Fi network model Analysis of the throughput and delays in different transmission scenarios Realization of QoS requirements needs adaptive software for access points

Thank you!