Saint Petersburg State University of Telecommunications Roman V

Saint Petersburg State University of Telecommunications Roman V. Plyaskin romick 2000@yandex. ru Advisor: Prof. Alexander E. Ryzhkov

Outline Review of Wi-Fi networks IEEE 802. 11 standard Qo. S in Wi-Fi networks A Wi-Fi network model

Review of Wi-Fi networks Museums Hospitals Conferences

Hotspots Airports Hotels Cafes

Russian operators Aeroport Peter-star Aist Polyarnaya Zvezda Art. Communications Quantum Avantel Rambler Telecom City. Net Rinet Comstar United Telesystems RISS Telecom Equant RTComm-Yug e. Wi-Fi Samara Internet Golden Telecom South Telecommunications Company Infotecs Taganrog Telecom Stelcom Mega. Fon Tascom Moscom Vimpelcom MTS Wi-Finder MTU-Intel** Wiland Netprovodov. ru Zebra Telecom Source: J'son & Partners

Top Russian Wi-Fi providers Rank 1. 2. 3. 4. 5. 6. 7. Company Tascom Quantum Moscom Stelcom Golden Telecom Peterstar EWi-Fi City Moscow St. Petersburg Moscow Hotspots 40 22 20 17 15 St. Petersburg Moscow 11 10 Source: J'son & Partners

Two models of Wi-Fi services providing Commercial Noncommercial 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 Rank Company City Commercial Free-ofcharge * Test 1. Tascom Moscow 11 29 21 2. Quantum St. Petersburg 22 - n/a 3. Moscom Moscow 20 - 15 4. Stelcom Moscow 17 - 9 5. Golden Telecom Moscow 10 5 6 6. Peterstar St. Petersburg 11 - 5 7. EWi-Fi Moscow 10 - n/a Sources: Company Data, J'son & Partners

Source: J'son & Partners

Number of hotspots Source: J'son & Partners

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 25 -30 thousands Wi-Fi users by the end of 2008 According to Broad. Group 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%.

IEEE 802. 11 standard The scope of the standard 802. 11 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.

infrastructure network AP DS STA 1 BSS 1 AP ESS STA 3 STA 2 BSS 2

Ad hoc network STA 1 STA 2 BSS 1 STA 3 STA 4 STA 5 BSS 2

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

802. 11 b wireless networks Data rate, Mbps Code sequence Modulation 1 11 chips (Barker code) DBPSK 2 11 chips (Barker code) DQPSK 5, 5 8 chips (СCK) DQPSK 11 8 chips (СCK) DQPSK

802. 11 g wireless networks Data rates, Mbps Modulation Obligatory Optional 1 Barker code 2 Barker code 5, 5 CCK РВСС 6 ERP-OFDM DSSS-OFDM 9 ERP-OFDM, DSSS-OFDM 11 CCK РВСС 12 ERP-OFDM DSSS-OFDM 18 ERP-OFDM, DSSS-OFDM 22 РВСС 24 ERP-OFDM DSSS-OFDM 33 РВСС 36 ERP-OFDM, DSSS-OFDM 48 ERP-OFDM, DSSS-OFDM 54 ERP-OFDM, DSSS-OFDM

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

Demand for Wi-Fi multimedia applications is growing rapidly due to: • 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

Enterprise market • cost savings • prioritized traffic management Public market Users are increasingly accustomed to Vo. IP 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 categories Access Category Description 802. 1 D tags Voice Highest priority. Allows multiple concurrent Vo. IP calls, with low latency and toll voice quality 7, 6 Video Prioritize video traffic above other data traffic. One 802. 11 g or 802. 11 a channel can support 3 -4 SDTV streams or 1 HDTV streams 5, 4 Best Effort Background Traffic from legacy devices, or traffic from applications or devices that lack Qo. S capabilities. Traffic less sensitive to latency, but affected by long delays, such as Internet surfing Low priority traffic (file downloads, print jobs) that does not have strict latency and throughput requirements 0, 3 2, 1

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) t TXOP STA 1 ACK frames Beacon Data Frames CF - End Beacon Station 1 (MPEG-4) Other stations (Internet data)

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

Scenario 1. Throughput

Scenario 1. Delays

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

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 Qo. S 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 Qo. S requirements needs adaptive software for access points

Thank you!