TELKOM Training Center Bandung 2005 KONSEP DASAR WiFi TELKOM Training Center Bandung 2005

Perbedaan Wired vs WLAN

Wireless LANs: KARAKTERISTIK TIPE Infrastructure based Adhoc KEUNTUNGAN Flexible deployment Minimal wiring difficulties More robust against disasters (earthquake etc) Historic buildings, conferences, trade shows,… KERUGIAN Low bandwidth compared to wired networks (1-10 Mbit/s) Proprietary solutions Need to follow wireless spectrum regulations

WIRED VS WLAN Hub Server Cisco Switch Internet Cisco Access Point Ethernet Client Wired LANs require that users locate in one place and stay there WLANs are an extension to the wired LAN network WLANs can be an overlay to or substitute for traditional wired LAN networks With Cisco Wireless LANs, portable PC users can: Move freely around a facility Enjoy real time access to the wired LAN, at wired Ethernet speeds Access ALL the resources of wired LANs

Wired vs Wireless Wired Wireless Instalasi Relative lebih sulit Lebih mudah Fleksibilitas Terbatas Lebih fleksibel Cost Lebih murah Lebih mahal Performance Sangat bagus bagus Maintenance Cukup besar Lebih kecil Security Cukup bagus Mobility Terbatas (tidak memungkinkan) Mendukung (jarak 100 m dari AP)

PERSAMAAN WIRED DAN WIRELESS Ethernet LAN Wireless LAN B A B C A C If both A and C sense the channel to be idle at the same time, they send at the same time. Collision can be detected at sender in Ethernet. Half-duplex radios in wireless cannot detect collision at sender.

SPEKTRUM WiFi Presentation_ID © 2000, Cisco Systems, Inc. 7

ISM Unlicensed Frequency Bands Short Wave Radio FM Broadcast Infrared wireless LAN AM Broadcast Television Audio Cellular (840MHz) NPCS (1.9GHz) 902-928 MHz 26 MHz 2.4 – 2.4835 GHz 83.5 MHz (IEEE 802.11) 5 GHz (IEEE 802.11) HyperLAN HyperLAN2 Extremely Low Very Low Low Medium High Very High Ultra High Super High Infrared Visible Light Ultra- violet X-Rays There are three unlicensed bands - 900 MHz, 2.4 GHz, and 5.7 GHz within the Industry, Medical and Scientific Frequency This presentation focuses on 2.4 GHz because our products use those bands today and it adheres to the IEEE 802.11b standard. The 5.7 GHz band is promising for future products and we are actively pursuing projects in that area. Recently, the FCC also opened up the 5.2 GHz band for unlicensed use by high speed data communications devices. 5.2 GHz is the same band that is used for the ETSI HYPERLAN specification in Europe. A nearby neighbor of the 900 MHz band is the cellular phone system. This helped the early development of the WLAN industry in the 900 MHz band because of the availability of low cost small RF components in that band. 2.4GHz has a neighbor in the PCS system. That helps with component costs too. There are no such neighbors for the 5 GHz band. The WLAN industry will have to driver the development of low cost components for 5GHz on our own. We think this means practical, cost effective, PCMCIA products in the 5 GHz band are a few years away. The other downside to 5GHz is the poor range performance as compared to 2.4GHz.

Spread Spectrum Approaches Direct Sequence Frequency Hopping The deciding factor is price/performance. DS generally delivers higher performance in range and throughput.

DS vs. FH: Ketahanan Terhadap Interferensi Frequency Hopping Direct Sequence Channel 1 2.4835 GHz 2.4835 GHz 1 2 3 Channel 2 Frequency Frequency Channel 3 2.4 GHz 2.4 GHz DS “muscles through” the interference, whereas FH hops around the interference. A DS system can also bet set to a different channel to avoid the interference altogether. Many cordless phones today are starting to operate in the 2.4 GHz band using FH technology. The FH phone is far more likely to experience interference from the DS system than vice versa. Time FH system hops around interference Lost packets are re-transmitted on next hop Data may be decoded from redundant bits Can move to an alternate channel to avoid interference

Frequency Hopping 9 8 7 6 5 4 3 2 1 79 Channels, 1 MHz Each Time 5 4 3 2 1 2.400 GHz 2.483 GHz With Frequency Hopping, the FCC requires the use of 75 different channels before repeating the use of any one channel. The maximum time on any one frequency is 400mS in any 30 second period. 802.11 has defined 26 hopping patterns in three different sets. These 26 patterns are designed to have minimum interference with each other. These patterns are called orthogonal patterns. If interference appears on a frequency, any data for that frequency is impaired, and will be retransmitted on the next frequency. Frequency 79 Channels, 1 MHz Each Changes frequency (Hops) at least every 0.4 seconds Synchronized hopping required

ALOKASI FREKUENSI WLAN

Scalability FH VS DS DS evenly inclines to a maximum of 3 Access Points per Cell Area. Using 2 Mbps technology, a FH product will outperform a DS product operating at 2MB in a scalability test. However, with the ability to have 11Mbps products in the same cell, you can obtain 33 Mbps of datarate. FH curves up and peaks with 15 systems allowing a maximum data rate of 24 Mbps. After that point is reached, there are more collisions that occur on the RF which brings down the overall effective data rate. This is very similar to adding more stations to an already fully utilized shared Ethernet network. More collisions occur, and throughput actually goes down.

Distribusi kanal berdasarkan ETSI Center frequency Channel number Bottom of channel Top of channel 1 2412 2401 2423 2 2417 2406 2428 3 2422 2411 2433 4 2427 2416 2438 5 2432 2421 2443 6 2437 2426 2448 7 2442 2431 2453 8 2447 2436 2458 9 2452 2441 2463 10 2457 2446 2468 11 2462 2451 2473 2400 MHz 2484 MHz ISM Band 12 2467 2456 2478 13 2472 2461 2483

Distribusi Kanal berdasarkan FCC 1 2412 2401 2423 2 2417 2406 2428 3 2422 2411 2433 4 2427 2416 2438 5 2432 2421 2443 6 2437 2426 2448 7 2442 2431 2453 8 2447 2436 2458 9 2452 2441 2463 10 2457 2446 2468 11 2462 2451 2473 2400 MHz 2484 MHz ISM Band Channel number Top of channel Center frequency Bottom of channel

Kanal 802.11b Perbandingan Teknologi WLAN • (14) 22 MHz wide channels (11 under FCC/ISTC) • 3 non-overlapping channels (1, 6,11)

Distribusi Kanal Global Channel ID ETSI FCC France Japan 1 2412 - 2 2417 3 2422 4 2427 5 2432 6 2437 7 2442 8 2447 9 2452 10 2457 12 2467 13 2472 14 2484 11 2462

Komponen/elemen Wi-Fi

KOMPONEN WLAN Access Point (sentral WLAN) AP dapat difungsikan sebagai Bridge, Point to Point atau Point to MultiPoint. Komponen ini sebagai interface antara station satu dengan lainnya yang tersambung secara wireless. Disamping itu AP merupakan jembatan penghubung ke jaringan wired LAN yang sudah ada. Card WiFi (untuk dipasang di station) NIC wireless LAN dipasang di sisi station dapat berupa PCMCIA card, USB card atau PCI card. Station Station yang dimaksud di sini dapat berupa PC (desktop), notebook atau PDA yang telah dilengkapi dengan interface WLAN. Asesories

CONTOH PERANGKAT WLAN

CPE WIRELESS LAN

STANDARD WIFI DAN GENERIKNYA

Personal Operating Space Klasifikasi Wireless WWAN GSM/ GPRS / CDMA WMAN IEEE802.16 WLAN IEEE802.11 HyperLan WPAN Bluetooth WAN WAN-MAN PAN MAN MAN-LAN LAN-PAN Pico-Cell Personal Operating Space ~50km ~2km 0km ~10m Courtesy of IEEE 802.15, Jan. 2001

W-LANA Merupakan asosiasi edukasi bersifat non profit Misi : Mengedukasi pasar mengenai Wireless LAN Menyediakan informasi tentang aplikasi, issue dan trend Wireless LAN. Merupakan sumber informasi bagi customer, industry, press dan analysts Anggota : 32 perusahaan

WECA Dibentuk pada tahun 1999 Mengintroduksi Wi-Fi (Wireless Fidelity) sebagai nama populer dari Wireless LAN IEEE 802.11b Misi : Mengetes dan memberikan sertifikasi interoperability bagi produk-produk Wi-Fi Mempromosikan Wi-Fi sebagai standard global Wireless LAN Anggota : 157 perusahaan Laboratorium testing di USA dan UK, selanjutnya akan dibuka di Tokyo dan Singapura mengingat 45% produk Wi-Fi berasal dari Asia

ISU INTEROPERABILITY WECA mengumumkan pada pertengahan 2001 bahwa 93 jenis produk W-LAN telah melewati test sertifikasi Wi-Fi Contoh peroduk yang telah memperoleh sertifikasi Wi-Fi : Cisco, Cabletron, 3 Com, Fujitsu, Avaya, NEC, Nokia, Lucent, Siemens, Samsung, Flexuscom, Zixel, Xircom, Compaq, NestComm, Proxim, Symbol Technology, etc Sertifikasi IEEE 802.11a / Wi-Fi5 oleh WECA dimulai pada September 2002

PENGEMBANGAN STANDAR WECA mulai melakukan sertifikasi interoperability terhadap produk IEEE 802.11a / Wi-Fi5 pada September 2002 Organisasi IEEE sedang mengembangkan standard baru disebut IEEE 802.11g untuk wireless LAN kecepatan tinggi berbasis OFDM yang bekerja pada frekuensi 2,4 GHz

Generik IEEE 802.11 Standards Descriptions 802.11c Improves interoperability 802.11d Multiple Regulatory Domains (Improve Roaming; New country) 802.11e Quality of Service (QoS); prioritizing voice or video 802.11f Inter-Access Point Protocol (IAPP) 802.11h Supports measuring and managing the 5-GHz radio signals in 802.11a 802.11i Enhanced Security (repairs WEP weakness) 802.11j Extensions for Japan 802.11k Passing specific radio frequency health and management data to higher-level management apps.

Generik IEEE 802.11 Standards Band (GHz) Raw Throughput 802.11 2.4 2Mbps (Legacy) 802.11a 5 54Mbps 802.11b 11Mbps 802.11g 802.11n ?? 100 Mbps

SEJARAH : 802.11 Legacy 1997: Standard Awal Nama Standard : IEEE 802.11-1997 Updated: IEEE 802.11-1999 Starting Point untuk “Standard-based WLAN” Untuk 2 Mbps: Direct sequence Spread Spectrum (DSSS) modulation Untuk 1-2 Mbps Frequency Hopping Spread Spectrum (FHSS) Keduanya menggunakan ISM band 2.4 GHz

802.11a 802.11b 802.11g KARAKTERISTIK 802.11 (1) Frekuensi 5 GHz Data rate 54 Mbps 11 Mbps Modulasi OFDM CCK OFDM/CCK Security WEP (WPA) WEP (WPA),11i Available bandwidth 300 MHz 83,5 MHz Data Rate Per Channel 6,9,12,18,24,36, 48,54 Mbps 1,2,5,11 Mbps 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, 54 Mbs WEP (WPA), 11i Kompatibilitas Tidak kompatibel b mature Kompatiel b Coverage 25-50 m 30-75 m Jumlah non overlapping channel 8 3 Harga Lebih mahal (sedikit vendor) Murah Agak mahal

KARAKTERISTIK 802.11 (2) Maximum throughput Max Link Rate Theoritical Max TCP Rate Thoeritical Max UDP Rate 802.11b 11 Mbps 5,9 Mbps 7,1 Mps 802.11g 54 Mbps 24,4 Mbps 30,5 Mbps 802.11a Maximum throughput

KARAKTERISTIK 802.11b 802.11b-1999 Range 50 – 100 m. (depends on obstacles) Omnidirectial antenna Indoor / Outdoor / Point-to-point (high-gain external antennas) Max throughput of 11 Mbit/s (5.5, 2,1 Mbps) Attenuation: Metal, Thick walls, Water, etc. ISM Band 2.4 GHz; DSSS; CSMA/CA 14 overlapping ch. (Different ch.for different countries) 3 simultaneously ch. (such as 1, 6, and 11) Proprietary speed extension "802.11b+" (22, 33 and 44 Mbit/s) Kompatible dengan standard asli 802.11 DSSS. Area coverage lebih luas dapat digunakan untuk ruangan terbuka, semi terbuka atau pun bersekat Bersifat cost effective dengan harga yang rendah dan coverage yang luas Sudah banyak diimplementasikan sehingga memungkinkan roaming antar zona W-LAN Interoperability memungkinkan implementasi dengan produk yang bervariasi (multi vendor)

KARAKTERISTIK 802.11a 2001 (802.11a-1999) Max throughput of 54 Mbps (Normally around 20 Mbps) ISM Band 5 GHz (FCC may open more spectrum) Mempunyai lebih banyak non-overlapping channel (12 nonoverlapping channels) 8 dedicated to indoor 4 to point to point Not widely deployed (US. / Japan) 802.11b popularity Less range / More attenuation Lack of roll back compatibility (now support a,b,and g) In Europe considering HiperLan2 Dapat digunakan komplemen jaringan 802.11b Potensi Interferensi lebih sedikit (5 GHz) Tidak kompatible dengan standar sebelumnya (802.11b) Bandwidth besar dengan area coverage terbatas, sesuai untuk ruangan dengan tingkat kepadatan user yang tinggi Dapat digunakan untuk aplikasi dengan bandwidth tinggi spt video stream, ftp dll Penambahan jumlah Access Point untuk memperbesar coverage

KARAKTERISTIK 802.11g 3rd quarter 2003 ISM Band 2.4 GHz Max throughput of 54 Mbps (Net 24.7 Mbps) Dual-band / Tri-mode supporting a, b, and g A single wireless card / Access point Kompatibel dengan 802.11b Transfer data lebih besar dibanding 802.11b Dengan speed 802.11a dapat menjangkau coverage yang lebih luas Lebih cepat dibandingkan dengan 802.11b (54Mb vs 11Mb) Support 802.11 i

KELEBIHAN & KEKURANGAN 802.11a Spektrum lebih besar dibanding 802.11b Dapat digunakan dikomplemen jaringan 802.11b Bandwidth yang lebih besar (54 Mb) Potensi Interferensi lebih sedikit (5 GHz) Mempunyai lebih banyak non-overlapping channel Kelemahan Area jangkauan sempit Tidak kompatible dengan stadard sebelumnya

KELEBIHAN & KEKURANGAN 802.11b Reliable Jangkauan luas Mudah diintegrasikan dengan jaringan yang Menggunakan kabel. Kompatible dengan standard asli 802.11 DSSS. Kekurangan: Kecepatan lebih rendah (11 Mbps)

KELEBIHAN & KEKURANGAN 802.11g Kompatibel dengan 802.11b Transfer data lebih besar dibanding 802.11b Jangkauan lebih besar dibanding 802.11a Lebih cepat dibandingkan dengan 802.11b (24Mb vs 11Mb) Kekurangan Frekuensi crowded

Data rates and Range Source: Proxim

PERBANDINGAN COVERAGE

WLAN Goal Komplemen wired LANs Dua Alasan Utama : Mendukung mobilitas user & Peningkatan produktifitas Fleksibilitas dalam instalasi pada situasi perkabelan yang sulit

Topologi Wireless LAN

APA ITU WIRELESS LAN Wireless LAN adalah sistem jaringan komputer dan shared network equipment lainnya yang memungkinkan untuk saling terhubung dan berkomunikasi tanpa melalui media transmisi kabel.

Apakah Wireless LAN? Berkaitan dgn: Tidak terkait dgn: Lokal, bukan area luas Dalam gedung atau area kampus utk pengguna mobile Beberapa km utk point-to-point (LAN to LAN) Radio atau infrared Tidak perlu ijin Pengguna memiliki perangkatnya (tidak ada biaya pemakaian) Tidak terkait dgn: Seluler telepon Pager CDMA 3

DEFINISI Wireless LAN menggunakan gelombang radio electromagnetic untuk berkomunikasi dari suatu tempat ke tempat yang lain dalam model : Peer to Peer (Ad Hoc) Client Server Umumnya diimplementasikan sebagai jaringan Extension atau Alternative dari jaringan Wired LAN Frekuensi ISM (Industrial, Scientific and Medical) frequency bands - no licensing required 902-928 MHz, 2400-2483.5 MHz, 5725-5850 MHz

PERTANYAAN UMUM WLAN TANYA JAWAB Seberapa cepat? Maximum datarate Typical throughput 11/54 MB 5.5/27 MB Seberapa jauh ? Outdoors Indoors 3 km 100 m Seberapa banyak? Maximum clients per AP Typical clients per AP AP dalam satu lokasi 2048 Sama dengan ethernet 3 (b) The MOST Common questions: How fast, how far and how many! Note that we separate the ‘Sales’ term of datarate and the technical term ‘throughput’. Who really cares if the datarate is 1.6Mb but you only get 500KB throughput? There are systems out there that are NOT 802.11, with datarates at 1.6Mb but with throughput of only 500kb. That is a whopping 31% efficiency of the RF spectrum! Others claim 3Mb, but find that only works to about 30 ft. At the maximum rated distance they get a total of perhaps 300Kbps throughput! The questions to ask is: What is the throughput of the system at the MAXIMUM rated distance? With Cisco, ALL of our ratings are AT the maximum distance, unless specifically stated for a lower rate! How Many? That is a question that can only be answered by the customer and the integrator together. While the Cisco AP will allow 2048 associations with EACH AP in the system, the limiting factor is the applications. If the system is used for minimal usage (e-mail, net cruising etc.) then perhaps 50 users per AP can work fine. For high data applications, the 340 acts like a wired 10MB Ethernet segment!

2 Implementasi berbeda Wireless LAN Wireless Networking Koneksitas pengguna bergerak Wireless Bridging Koneksitas LAN - LAN

Local Area Network (LAN) Hub Server Switch Internet Access Point Wireless LAN (WLAN) sebagai ekstensi dari LAN fisik Ethernet Client

Topologi LAN Kanal 6 Kanal 1 Access Point Wireless “Cell” Pengguna Wireless LAN Backbone Kanal 1 penggunaWireless

Topologi Repeater Wireless Kanal 1 Access Point Wireless Clients Wireless Repeater “Cell” LAN Backbone

Topologi Wireless LAN Kanal 6 Kanal 1 Wireless “Cell” LAN Backbone Access Point Wireless “Cell” Kanal 6 Wireless Clients LAN Backbone Kanal 1

Topologi Sistem Redudansi LAN Backbone Channel 1 Channel 6 In Wireless Clients

Konfigurasi Peer to Peer Topologi Peer to Peer Konfigurasi Peer to Peer (Ad Hoc mode) Wireless “Cell” Wireless Clients Modem

Contoh Site Survey kanal Seting Kanal Contoh Site Survey kanal Channel 1 Channel 11 Channel 6 Channel 11 Channel 6 Channel 6 Channel 1 Channel 11 Channel 1 Channel 11

Cakupan Access Point & Kecepatan Data 1 Mbps DSSS 2 Mbps DSSS 5.5 Mbps DSSS 11 Mbps DSSS

Implentasi Multi-rate Contoh Site Survey Bandwidth 5.5 Mbps 11 Mbps 2 Mbps

Arsitektur Micro selular Internet

Microcellular Architecture Roaming Internet

Coverage Access Link (AL) dari AP WIRELESS MESH AP Transit Link (TL) @ 5 GHz Menggunakan 802.11a Coverage Access Link (AL) dari AP Access Link (AL) @ 2.4 GHz Menggunakan 802.11b MN MN Mobile Node (MN)

Keuntungan & Kerugian

Kelebihan WLAN vs Wired Plug and play : dapat digunakan secara langsung Meningkatkan produktivitas and Layanan (Mobility): Akses informasi secara Real-Time Dapat mengakses darimana pun dalam area organisasi/ kantor Kecepatan instalasi : dibandingkan penggelaran jaringan kabel yang membutuhkan waktu yang lama Flexibel : Dapat digelar dimana saja bahkan di tempat dimana kabel tidak mungkin diimplementasikan Reduksi biaya : Dalam kasus pengembangan, pemindahan maupun perubahan konfigurasi LAN

MENGATASI KERUMITAN INSTALASI KABEL

MENGATASI KERUMITAN INSTALASI KABEL

KERUGIAN WLAN Low bandwidth dibanding dengan jaringan kabel Frekuensi bebas Isu keamanan Harga awal lebih mahal

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