... chuẩn 802. 16 (WiMax) 23 Hình 2. 1 Các chuẩn giao thức IEEE 802. 11 mô hình OSI .25 Hình 2.2 Mô hình kiến trúc theo chuẩn 802. 11 .26 Hình 2. 3: Các lựa chọn chuẩn 802. 11b 28 ... tần số 2, 4 GHz 802. 11b, hệ thống sử dụng 802. 11g dễ bị nhiễu 802. 11b 2.2 .2 Nhóm lớp liên kết liệu MAC a, Chuẩn 802. 11d Chuẩn 802. 11d bổ xung số tính lớp MAC nhằm phổ biến WLAN toàn giới Một số ... thức IEEE 802. 11 mô hình OSI .25 Hình 2.2 Mô hình kiến trúc theo chuẩn 802. 11 .26 Hình 2. 3: Các lựa chọn chuẩn 802. 11b 28 Hình 2. 4 Định dạng frame quy định FHSS 802. 11 PHY...
... adapt and copy a portion of the specification as the base material for 802. 15.1 • 802. 15.1 standard – Approved in March 2, 20 02 – Fully compatible with Bluetooth version 1.1 Bluetooth Protocol Stack ... speed RF WPANs • Offer functionality beyond that of IR devices • Include – Bluetooth – 802. 15.4 (ZigBee) IEEE 802. 15.1 and Bluetooth • Industry specification – Bluetooth Special Interest Group (SIG) ... at a speed of up to Mbps Bluetooth version 2. 0 transmits at or Mbps 10 Bluetooth Protocol Stack (continued) 11 Bluetooth Protocol Stack (continued) 12 Bluetooth Protocol Stack (continued) 13 Bluetooth...
... two standards – IEEE 802. 15.3 and 802. 15.5 • IEEE 802. 15.3 standard – Defines the specifications for HR WPANs supporting speeds of 11, 22 , 33, and up to 55 Mbps • In the 2. 4 GHz ISM band Wireless# ... with 802. 11a networks • ZigBee and WiMedia products should be able to coexist with 802. 11b/g without any serious problems Wireless# Guide to Wireless Communications 42 Summary • IEEE 802. 15.3 -20 03 ... two different channel plans – Works in the same ISM band as 802. 11b WLANs • 802. 15.3 supports peer-to-peer or ad hoc networks • 802. 15.3 piconets support child and neighbor piconets Wireless#...
... thông, công nghệ điện, điện tử với mạng LAN Cho đời chuẩn có tên gọi dự án 802 : 802. 3; 802. 4; 802. 5; 802. 11 Trong 802. 11 chuẩn cho mạng cục không dây, có nhiệm vụ định nghĩa các đặc tả tầng vật ... chiếu OSI chuẩn 802. 11 Hình 2. 6 IEEE 802. 11 mô hình OSI Các chuẩn IEEE 802. 11: • 802. 11a : Là chuẩn cho WLAN, dải băng GHz, tốc độ liệu tối đa 54Mbps, phê chuẩn năm 1999 • 802. 11b : Là chuẩn ... Chương bao gồm chủ đề sau: Tổng quan Topologies WLAN 11 802. 11 Phương thức truy nhập môi truờng 802. 11 Vận hành lớp MAC 802. 11 Định dạng khung 802. 11 WLAN ngày trở nên phổ biến sông, triển khai mạng...
... unused wires in a standard UTP Ethernet cable 11 WLAN Modes • Ad hoc mode • Infrastructure mode 12 Ad Hoc Mode • Also known as peer-to-peer mode – Formal name: Independent Basic Service Set (IBSS) ... wired NIC • Access points parts – Antenna – Radio transceiver – RJ-45 wired network interface 18 ...
... distances – LMDS used the following ranges of frequencies • 27 .5 MHz and 28 .35 MHz • 29 .1 MHz and 29 .25 MHz • 30 GHz, 31.075 GHz, and 31 .22 5 GHz • Architecture – Cells (like a cellular telephone ... sharing Security Availability of the technology 17 IEEE 802. 16 (WiMAX) • Standard for wireless broadband metropolitan area networks • 802. 16 supports enhancements and extensions to the MAC protocols ... WiMAX Forum – Promotes the implementation of 802. 16 by testing and certifying equipment • WiMAX stands for worldwide interoperability for microwave access 18 WiMAX Applications • Applications – Suitable...
... latitudes – Orbits typically have a 24 -hour period 38 Geosynchronous Earth Orbit (GEO) • Geosynchronous earth orbit (GEO) satellites – Stationed at an altitude of 22 , 28 2 miles – Orbit matches the rotation ... FDMA and TDMA technologies 14 2. 5 Generation Cellular Telephony • 2. 5 Generation (2. 5G) – – – – Interim step between 2G and 3G Operates at a maximum speed of 384 Kbps 2. 5G networks are packet-switched ... connection 15 2. 5 Generation Cellular Telephony (continued) • 2. 5G network technologies – General Packet Radio Service (GPRS) • For TDMA or GSM 2G networks • Uses eight time slots in a 20 0 KHz spectrum...
... loạt theo kiểu virus để ngăn sự phá hoại Ngoài ta khai báo thêm số thông số bấm vào nút Advanced • Số email gửi lần • Số người nhận email • Đối chiếu với danh sách người gửi Privacy: Các ... Remove để khoá mở khoá cho website hay địa IP máy Program Control: Cho phép ta thiết lập thông số nhằm kiểm soát việc thực thi chương trình máy tính nhằm tránh xâm nhập trái phép từ hacker tránh ... Internet Email Protection: Mục nhằm bảo vệ an toàn cho hệ thống thư điện tử Ta thiết lập thông số cho mục: • Inbound MailSafe protection : Bảo vệ an toàn máy tính theo cách không cho mở...
... Overview of the IEEE P8 02. 15 Working Group for Wireless Personal Area Networks, IEEE Personal Communications, February, 20 00, 37–43 [4] IEEE Project 802. 15 http://www.ieee8 02. org/15 [5] Heile B., ... IEEE 802. 11 the operation of CSMA/CA for HomeRF is not discussed here in detail However, we note the following difference in the contention period of HomeRF 2. 0 compared with that of IEEE 802. 11 ... and security are also discussed Personal Area Networks (PANs) 325 WWW Resources www.ieee8 02. org/15: the web site of working Group 802. 15 which deals with PAN standardization www.bluetooth.com:...
... 1996 27 2 Wireless Networks [ 12] Kahol A., Khurana S and Jayasumana A P Effect of Hidden Terminals on the Performance of IEEE 802. 11 MAC Protocol, in Proceedings of IEEE LCN 98, 19 98, pp 12 20 [13] ... propagation 9.6 .2 802. 11b Another recent development is the IEEE 802. 11b specification Like 802. 11a, it is also a specification for the physical layer It operates in the unlicensed 2. 4 GHz band The ... from 802. 11a and 802. 11b, will increase the performance of 802. 11 networks 9.6.4.3 Task Group f This project proposes to specify the necessary information that needs to be exchanged between 802. 11...
... Networking 20 11, 20 11: 58 http://jwcn.eurasipjournals.com/content /20 11/1/ 58 Page 10 of 12 5.4 ) 5.3s b p M 5 .2( T 5.0 h r o u g 5.1 h p u t tneilC redivorP rehtO noitageled o/w 0001 0 08 006 004 0 02 Δ ... Proceedings of ISCC 20 04, 760–765 (July 20 04) 10 J Valdez, M Guirguis, Liberating TCP: the free and the stunts, in International Conference on Networking, 20 08, ICN 20 08, 72 77 (Apr 20 08) 11 P Liu, ... 802. 11a WLAN with physical transmission rate of 24 Mbps Nishio et al EURASIP Journal on Wireless Communications and Networking 20 11, 20 11: 58 http://jwcn.eurasipjournals.com/content /20 11/1/58...
... 22 59 38 and the project SENSEI with Grant no 21 5 923 References [1] N Davies, D P Siewiorek, and R Sukthankar, “Activity-based computing,” IEEE Pervasive Computing, vol 7, no 2, pp 20 – 21 , 20 08 ... ports 1 92 µs — Computes the energy in a frequency band from FFT data 20 0 µs 12 Computes a 32 bit real-valued FFT over a data window of n = 2k samples (exec time for FFT 186 ms 16 + 4n + ns 1 28 16-bit ... module provides 48 k ROM and 10 k RAM Platform TinyOS∗ TinyOS with Deluge Mat´ e Titan firmware dynamic memory packet memory ROM 16 520 26 89 6 37004 35 024 RAM 541 1 089 3146 1 422 +4096 +1440 ∗ As...
... (Mbps) 25 20 15 25 20 15 10 10 5 20 40 60 80 Number of aggregated MPDUs 20 40 60 80 Number of aggregated MSDUs BER= BER= 1E − BER= 4E − BER= 8E − BER= 2E − BER= BER= 1E − BER= 4E − BER= 8E − BER= 2E ... adaptation for IEEE 802. 11 a wireless LANs,” IEEE Transactions on Mobile Computing, vol 1, no 4, pp 27 8 29 2, 20 02 [22 ] J D P Pavon and S Choi, “Link adaptation strategy for IEEE 802. 11 WLAN via received ... ’ 08) , pp 24 54 24 59, May 20 08 [20 ] A Kamerman and L Monteban, “WaveLAN -II: a highperformance wireless LAN for the unlicensed band,” Bell Labs Technical Journal, vol 2, no 3, pp 1 18 133, 1997 [21 ]...
... Applications, SENSORCOMM ’ 08, Cap Esterel, France, 20 08, pp 20 9 21 6 [2] IEEE 802. 15.6, Application summary, 15- 08- 0406-00-0006-tg6-applicationsmatrix.xls, 20 08 [3] IEEE 802. 15.6, Technical requirement ... calculated using (20 ) to (25 ) The average power consumption for transmitting the data packet and receiving the Ack packet can be calculated using (21 ) and (22 ) (20 ) (21 ) (22 ) Power consumed due ... Biomed 13(6), 915– 925 (20 09) [13] M Miller, N Vaidya, A MAC protocol to reduce sensor network energy consumption using a wakeup radio IEEE Trans Mobile Comput 4(3), 22 8 24 2 (20 05) [14] I Demirkol,...