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Nyoman Suryadipta, ST, CCNA , CCNP

Chapter V & VI Satellite & WLAN. Nyoman Suryadipta, ST, CCNA , CCNP. Satellite. Basics of Satellites Types of Satellites Capacity Allocation. Global . Suburban . Urban . In. -. Building . Micro. -. Cell . Home Cell. -. Macro. -. Cell . Pico. -. Cell . Terrestrial

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Nyoman Suryadipta, ST, CCNA , CCNP

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  1. Chapter V & VI Satellite & WLAN Nyoman Suryadipta, ST, CCNA, CCNP

  2. Satellite • Basics of Satellites • Types of Satellites • Capacity Allocation

  3. Global Suburban Urban In - Building Micro - Cell Home Cell - Macro - Cell Pico - Cell • Terrestrial • Cooper & Cable, limited for urban areas with legacy apps • High cost and build for backbone infrastructure • Enhanced with xDSL technology, but limited by line distance, quality, and availability • Enhanced with FWA, but limited by population density and technological challenges • Satellite • Alternatif solution for terrestrial last mile bottlenecks • For areas undeserved economically by terrestrial • Quick infrastructure deployment ( time consideration ) • End to end based networks • Direct to user/home interactive applications • Temporally requirements

  4. Why Satellite • Two Stations on Earth want to communicate through radio broadcast but are too far away to use conventional means. • The two stations can use a satellite as a relay station for their communication

  5. Signal Transmission • One Earth Station sends a transmission to the satellite. This is called a Uplink. • The satellite Transponder converts the signal and sends it down to the second earth station. This is called a Downlink.

  6. Advantages • The coverage area of a satellite greatly exceeds that of a terrestrial system. • Transmission cost of a satellite is independent of the distance from the center of the coverage area. • Satellite to Satellite communication is very precise. • Higher Bandwidths are available for use. • The distance between an earth station and a satellite (free space).

  7. Dis - advantages • Launching satellites into orbit is costly. • There is a larger propagation delay in satellite communication than in terrestrial communication. • Atmospheric Attenuation caused by air and water can impair the transmission. It is particularly bad during rain and fog.

  8. Orbits • GEO • LEO • MEO

  9. Geostationary Earth Orbit (GEO) • These satellites are in orbit 35,863 km above the earth’s surface along the equator. • Objects in Geostationary orbit revolve around the earth at the same speed as the earth rotates. This means GEO satellites remain in the same position relative to the surface of earth.

  10. Medium Earth Orbit (MEO) • A MEO satellite is in orbit somewhere between 8,000 km and 18,000 km above the earth’s surface. • MEO satellites are similar to LEO satellites in functionality. • MEO satellites are visible for much longer periods of time than LEO satellites, usually between 2 to 8 hours. • MEO satellites have a larger coverage area than LEO satellites.

  11. Low Earth Orbit (LEO) • LEO satellites are much closer to the earth than GEO satellites, ranging from 500 to 1,500 km above the surface. • LEO satellites don’t stay in fixed position relative to the surface, and are only visible for 15 to 20 minutes each pass. • A network of LEO satellites is necessary for LEO satellites to be useful

  12. Frequency Bands • Different kinds of satellites use different frequency bands. • L–Band: 1 to 2 GHz, used by MSS • S-Band: 2 to 4 GHz, used by MSS, NASA, deep space research • C-Band: 4 to 8 GHz, used by FSS • X-Band: 8 to 12.5 GHz, used by FSS and in terrestrial imaging, ex: military and meteorological satellites • Ku-Band: 12.5 to 18 GHz: used by FSS and BSS (DBS) • K-Band: 18 to 26.5 GHz: used by FSS and BSS • Ka-Band: 26.5 to 40 GHz: used by FSS

  13. TOPOLOGY : STAR Palapa C2 TDM HX 50 TDMA IP Gateway Branch Enterprise Router HX Gateway FRAME RELAY MPLS INTERNET HX 50 Branch Outroute Inroute Head Office

  14. HX : Hub & Remote HX GATEWAY (HUB) HX 50 FRONT VIEW HX 50 REAR VIEW

  15. HX 50 : Indoor – Outdoor Connection Tx (coaxial) BUC Rx (Coaxial) LNB RF Unit Outdoor Unit LAN HX 50 Indoor Unit BUC : Block Upconverter LNB : Low Noise Blockdownconverter RF : Radio Frequency

  16. Early 1990’s : Legacy protocol (X.25/SDLC) : Data • Legacy Protocol • X.25/SDLC over VSAT • 2.4 Kbps – 64 Kbps • 2000 : IP Connectivity - Data • 2005 : IP Connectivity with QoS/CoS – Data & Voice • Access Method : • TDMA : Sharing Bandwidth – VSAT Net/VSAT IP/VSATMultiservices Total Remotes : + 1500 • FDMA : SCPC/Teleport – VSAT Link Total Remotes : + 300 • Transponder • Telkom 1 : PT. TELKOM • PALAPAC2 : PT. INDOSAT • Apstar : SingTel • Frequency bands : C-band – Linier polarization

  17. Study Case • Indonesia diketahuikehilanganpotensikehilanganpajakdaribiayahakpenggunaan (BHP) frekuensisebesarRp2,4triliunsetiaptahunkarenapenguasaan yang besaruntuksatelit broadcasting sebesar 150 MHz di pita 2,5 GHz.

  18. Study Case • Indonesia diketahuikehilanganpotensikehilanganpajakdaribiayahakpenggunaan (BHP) frekuensisebesarRp2,4triliunsetiaptahunkarenapenguasaan yang besaruntuksatelit broadcasting sebesar 150 MHz di pita 2,5 GHz.

  19. Study Case • Sekjen Indonesia Wireless Broadband (Idwibb) YohannesSumaryomengungkapkan di pita tersebut, terdapat PT Media Citra Indostar (Indovision) yang menguasaispektrumselebar 150 MHz danhanyabayarBHPsebesarRp300jutasetahun. • Sementaraoperator WiMaxatauLTEsanggupmembayarRp2,4triliun per tahununtuklebar pita yang sama

  20. Study Case • 1 BTS seluler 5 MHz bisauntukmelayanihingga 90 stasiunpelanggandalamsatu area yang sempit 3-5 km radius,

  21. Example • Indostar II dibuatoleh Boeing Satellite System di Los Angeles, California, AS, dalamwaktu 20 bulan, dengan total biayasebesar US$ 300 juta — darikas internal danpinjamanasing. Satelit yang memilikiumur orbit 16,8 tahunlebih. SatelitIndostar II inimenempati slot orbit 107,7 derajat BT danbekerja di pita frekuensi 2,5 GHz (2.520-2.670 GHz) selebar150 MHz. Source ; swa.co.id

  22. Example • satelit high power tersebutmemungkinkanIndovisionmenampungkapasitassiaranhinggalebihdari 120 channel. Saatini, jumlahkanal yang dimilikitelevisiberbayaritu 62. • Misal : 2,5 GHz / 120 channel = ± 20 MHz 1 kanaltransmisisiaran video satelitmembutuhkanlebar pita/bandwidth 20 MHz

  23. WLAN

  24. Benefits of Wireless • Mobility • Scalability • can be added to a network easily • use of “hotspots” • Flexibility • anytime, anywhere connectivity • Cost • inexpensive to install • reduced installation costs

  25. Limitations/Risks of Wireless • Uses unlicensed regions of the RF spectrum • used by many different devices • Interference • cordless phones • microwaves • Security • easy access to the network • encryption/authentication helps with security issues

  26. Wireless Technologies • WPAN • Wireless Personal Area Network • used for: • mice • keyboards • PDAs

  27. Wireless Technologies • WLAN • Wireless LAN • uses RF standards • conform to 802.11 standards • connects through Wireless AP

  28. Wireless Technologies • WWAN • Wireless WAN • coverage over large areas • cell phone network

  29. Components of a WLAN • Wireless client • any host that can participate in a wireless network • Access point (AP) • control access between wired and wireless networks

  30. Components of a WLAN • Wireless Bridge • connects two wired networks through a wireless link • offers long range connectivity • 25 miles • Uses unlicensed RF frequencies

  31. Access Point • Antennas • increases output signal strength (gain) • receives the wireless signal • higher gain = increased distance • Directional antenna • concentrates signal in one direction • allows for greater distances • Omni-directional antenna • emits signal equally in all directions • used by most Access Points

  32. Purpose of SSID • Service Set Identifier • Allows wireless components to connect to the WLAN • tells wireless devices which WLAN they belong to • tells devices whom then can talk to • All wireless devices must have same SSID to communicate with each other • Characteristics • case sensitive • alphanumeric characters • sent in the header of the frame

  33. Infrastructure Installation • Used by larger networks • Uses an Access Point (AP) • makes sure all STAs have equal access • Each device must receive permission to communicate • BSS • Basic Services Set • area covered by a AP

  34. Channels in a WLAN • Use of channels help to control conversations • allows multiple Access Points close to one another to function • each AP must be on different channel • Each channel capable of carrying a different conversation

  35. CSMA/CA • Carrier Sense Multiple Access with Collision Avoidance • Ensures collisions do not occur on a wireless network • Reserves a channel for communication • Device requests permission from AP (Request to Send–RTS) • If available, AP responds with all clear message • Clear to Send Message (CTS) • CTS is broadcast to all other devices • informs everyone the channel is being used • Upon completion of conversation • Device that requested channel send ACK to AP • ACK indicates to AP that channel can be used again • ACK sent to other devices letting them know the channel can be used again

  36. IEEE 802.11 WLAN Standard Activities Legend Ratified Draft 18 Months and Beyond • 802.11a: 5 GHz, 54 Mbps • 802.11b: 2.4 GHz, 11 Mbps • 802.11d: Multiple regulatory domains • 802.11e: Quality of Service (QoS) • 802.11f: Inter-Access Point Protocol (IAPP) • 802.11g: 2.4 GHz, 54 Mbps • 802.11h: Dynamic Frequency Selection (DFS) and Tran Power • 802.11i: Security – Ratified | WPAv2 – Draft 9 • 802.11j: Japan 5 GHz Channels (4.9-5.1 GHz) • 802.11k: Measurement • 802.11m: Maintenance • 802.11n: High Throughput • 802.11p: Wireless Access for Vehicular Environment • 802.11r: Public WLAN Fast Roaming • 802.11s: Mesh Networking

  37. 802.11 a/b/g Specifications

  38. 802.11 a/b/g Range vs. Bandwidth 120/400 100/333 80/266 60/200 40/133 20/67 0 • 802.11a • 802.11b • 802.11g Distance (Meters/Feet) Bandwidth (Mbps) Note: Bandwidth is based on RF rates. Actual throughput is lower.

  39. WLAN Security Standards 1997 the original 802.11 standard only offers - SSID (Service Set Identifier) - MAC Filtering (Media Access Control) - and WEP (Wired Equivalent Privacy) 1999 several industry players formes WECA (Wireless Ethernet Compatibility Alliance) for rapid adaption of 802.11 network products. 2001 Fluhrer, Mantin and Shamir had identified some weaknesses in WEP. IEEE started Task Group i. 2002 WECA was renamed in WI-FI

  40. WLAN Security Standards 2003 Wi-Fi introduced the Wi-Fi Protected Access (WPA). - Should be an interim solution for the weakness of WEP. - Some parts of IEEE 802.11i. 2004 The WPA2 was introduced. - It based on the final IEEE 802.11i standard. - Was ratified on June 25.

  41. WLAN Security Standards WEP WPA WPA2 Cipher RC4 RC4 AES Key Size 40 or 104bits 104bits perPack 128bits encry. Key Life 24bit IV 48bit IV 48bit IV Packet Key Concatenation TwoPhaseMix Not Needed Data Integrity CRC32 Michael MIC CCM Key Management None 802.1X/EAP/PSK 802.1X/EAP/PSK

  42. Wireless Security • No physical connection needed • Attacker can “tune into” your network just like tuning into a radio station • Easy access if all settings are set to default, so . . . • CHANGE THE SETTINGS • disable SSID • change default password • change default IP • But . . • SSID transmitted in clear text • still possible to learn the SSID

  43. MAC Address Filtering • Another security feature • Will limit access to your network • MAC address used to identify which device can connect to the wireless network • wireless AP looks up MAC in a list (database) • only those addresses listed will gain access

  44. Security – Authentication • Controls who connects to the network • Permitted based on set of credentials • Helps to verify the “trustworthiness” of the device • usernames • passwords • Occurs before client is connected to WLAN

  45. Open Authentication • On by default • Any and all clients can access AP • Should only be used on public wireless networks • Schools • Internet Café

  46. PSK (Pre-Shared Keys) Authentication • Both AP and client must have the same secret key or word • Here’s how it works: • AP sends random string of bytes to client • Client accepts it, encrypts it, and sends it back to AP • AP receives encrypted string, decrypts it • if decrypted string = original string  client is added

  47. EAP (Extensible Authentication Protocol) • EAP software must be installed on the client device • Client talks with RADIUS Server • Remote Authentication Dial-in User Services • server functions separately from the AP • server keeps a database of valid users • username and password checked by the server

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