McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Chapter 15 Wireless LANs

McGraw-Hill The McGraw-Hill Companies, Inc., IEEE Architecture Physical Layer MAC Layer Addressing Mechanism

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.1 BSSs

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.2 ESS

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.3 Physical layer specifications

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.4 FHSS

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Frequency Hopping Spread Spectrum Dwell Time: 400 mseg Banda de 2.4 Ghz (ISM) 79 sub-bandas de 1 MHz FSK: 1 ó 2 bits por baud

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.5 DSSS

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Canales DSSS

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Direct Sequence Spread Spectrum b: HR-DSSS (High Rate DSSS) CCK (Complementary Code Keying) Símbolos de 4 u 8 bits 1 Mbps: BPSK 2 Mbps: QPSK 5.5 Mbps: BPSK (1.375 Mbaud; 4 bits CCK) 11 Mbps: QPSK (1.375 Mbaud; 8 bits CCK)

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.6 MAC layers in IEEE standard Distributed Coordination Function Point Coordination Function

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 ¿Por qué NO CSMA/CD? Transmitir y recibir al mismo tiempo. Tarjetas más caras y mayor capacidad “Estación escondida” “Estación expuesta” ABCD

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.7 CSMA/CA flowchart

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.8 CSMA/CA and NAV

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure 15.9 Frame format

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Table 15.1 Subfields in FC field When set to 1, means station has more data to send. More data Wired equivalent privacy. When set to 1, means encryption implemented. WEP Reserved.Rsvd Defined later. From DS When set to 1, means more fragments. More flag When set to 1, means retransmitted frame. Retry When set to 1, means station is in power management mode. Pwr mgt Defined later. To DS Defines the subtype of each type (see ). Subtype Type of information: management (00), control (01), or data (10). Type The current version is 0. ExplanationVersion Field

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Control frames

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Table 14.2 Values of subfields in control frames Acknowledgment (ACK) 1101 Clear to send (CTS) 1100 Request to send (RTS) Meaning 1011 Subtype

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Table 15.1 Subfields in FC field Sending AP Source station Sending AP Source station Address 2 Destination station Source station BSS ID Address 3 Source station N/A N/A N/A Address 4 Receiving AP Destination station Address From DS To DS

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Addressing mechanism: case 1

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Addressing mechanism: case 2

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Addressing mechanism: case 3

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Addressing mechanism: case 4

McGraw-Hill The McGraw-Hill Companies, Inc., Bluetooth Architecture Radio Layer Baseband Layer Other Upper Layers L2CAP Layer

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Piconet

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Scatternet

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Bluetooth layers

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Single-slave communication

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Multiple-slave communication

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure Frame format types

McGraw-Hill The McGraw-Hill Companies, Inc., 2004 Figure L2CAP data packet format