Chapter 6 Local Area Networks and Media Access Control. School of Info. Sci. & Eng. Shandong Univ.

Transcription

1 Chapter 6 Local Area Networks and Media Access Control School of Info. Sci. & Eng. Shandong Univ.

2 6.1 MULTIPLE ACCESS COMMUNICATIONS FIGURE 6.1 Multiple access communications

3 FIGURE 6.2 Approaches to sharing a Transmission medium

4 FIGURE 6.3 Satellite communication involves sharing of uplink and downlink frequency bands

5 FIGURE 6.4 Multidrop telephone line requires access control

6 FIGURE 6.5 Ring networks and mullilappcd buses require MAC

7 FIGURE 6.6 Wireless LAN

8 FIGURE 6.7 Channel capture and delay-bandwidth product where v is the.speed of light in the medium, typically 2 to 3 x 10 8 meters/second

9 TABLE 6.1 Number of bits in transit in one-way propagation delay assuming propagation speed of 3x 10 8

10 FIGURE 6.8 Typical frame transfer delay versus load (normalized throughput)

11 FIGURE 6.9 Dependence of delay-throughput performance on a = Rt prop /L

12 6.2 Local Area Networks FIGURE 6.10 Typical LAN structure and network interface card

13 FIGURE 6.11 IEEE 802 LAN standards

14 FIGURE 6.12 The MAC sublayer provides unreliable datagram service

15 FIGURE 6.13 The LLC can provide reliable packet transfer service

16 FIGURE 6.14 LLC PDU structure

17 6.3 RANDOM ACCESS FIGURE 6.15 LLC PDU and MAC frame

18 FIGURE 6.16 ALOHA random access scheme

19 FIGURE 6.17 Throughput S versus load G for ALOHA and slotted ALOHA

20 FIGURE 6.18 Slotted ALOHA random access scheme, (t 0 =(k+1)x)

21 FIGURE 6.19 CSMA random access scheme

22 FIGURE 6.20 p-persitenl CSMA random access scheme

23 FIGURE 6.21(a) Throughput S versus load for G for 1-Persistent and Non-Persistent CSMA. The curves are for different values of a'

24 FIGURE 6.21(b) Throughput S versus load for G for 1- Persistent and Non-Persistent CSMA. The curves are for different values of a'

25 l FIGURE 6.22 The reaction time in CSMA-CD is 2tprop

26 FIGURE 6.23 Packet transmission times and contention periods

27 FIGURE 6.24 Maximum achievable throughputs of random access schemes

28 6.4 SCHEDULING APPROACHES TO MEDIUM ACCESS CONTROL FIGURE 6.25 Basic reservation system

29 FIGURE 6.26 Operation of reservation system with negligible and non-negligible delays

30 FIGURE 6.27 Examples of polling systems

31 FIGURE 6.28 Interaction of polling messages and transmissions in a polling system

32 FIGURE 6.29 Packet delay for polling

33 FIGURE 6.30 Token-passing rings

34 FIGURE 6.31 Approaches to token reinsertion: (a)mulliloken. (b) single token, and (c) single packet

35 FIGURE 6.32 Throughput comparisons for single packet per token schemes

36 FIGURE 6.33 Mean wailing lime token ring. M = 32 stations, unlimited service/token FIGURE 6.34 Mean wailing lime for multiloken ring. M = 32. one packet/token

37 FIGURE 6.35 Mean wailing lime for single-packel loken ring. M = 32

38 6.5 CHANNELIZATION FIGURE 6.36 Frequency-division multiple access

39 FIGURE 6.37 Time-division multiple access

40 FIGURE 6.38 Code-division multiple access

41 FIGURE 6.39 A maximum-length sequence generator

42 FIGURE 6.40 Conceptual view of CDMA

43 FIGURE 6.41 Example of orthogonal coding for channelization

44 FIGURE 6.42 Example of channel signal recovery using orthogonal coding

45 FIGURE 6.43 Construction of Walsh-Hadamard matrices

46 FIGURE 6.44 AMPS frequency allocation and channel structure: (a) initial allocation; (b) extended allocation

47 FIGURE 6.45 IS-54 frame structure

48 FIGURE 6.46 (a) GSM channel structure; (b) GSM TDMA structure

49 FIGURE 6.47 IS-95 modulator for forward channel

50 FIGURE 6.48 IS-95 modulator for reverse channel

51 FIGURE 6.49 Comparison of FDMA. TDMA. and CDMA

52 FIGURE 6.50 Average delay for TDMA

53 6.6 LAN STANDARDS FIGURE 6.51 Frame transfer delay for Ethernet example

54 FIGURE 6.52 IIIEE MAC frame

55 FIGURE 6.53 Ethernet frame (DIX standard)

56 FIGURE 6.54 SNAP frame for encapsulating Ethernet frames

57 TABLE 6.2 IEEE Mbps medium alternatives

58 FIGURE 6.55 Ethernet cabling using thick and thin coaxial cable (Note: The T junction typically attaches to the NIC.)

59 FIGURE 6.56 Ethernet hub-and switch topologies using twistedpcabling

60 TABLE 6.3 IEEE 802.3u Fast Ethernet medium alternatives

61 FIGURE 6.57 Application of Fast Ethernet

62 TABLE 6.4 IEEE 802.3z Gigabit Ethernet medium alternatives

63 FIGURE 6.58 Token-ring network implemented using a star topology

64 FIGURE 6.59 Ring latency and token reinsertion strategies

65 FIGURE 6.60 Reinsert token after header of frame returns

66 FIGURE IEEE Token and data frame structure

67 FIGURE 6.62 FDDI token-ring network

68 FIGURE 6.63 FDD I frame structure

69 FIGURE 6.64 The hidden-station problem

70 FIGURE 6.65 Ad hoc network

71 FIGURE 6.66 Infrastructure network and extended service set

72 FIGURE 6.67 IEEE frame structure

73 FIGURE 6.68 IEEE MAC architecture FIGURE 6.69 Basic CSMA-CA operation

74 FIGURE 6.70 CSMA-CA

75 FIGURE 6.70

76 FIGURE 6.71 Transmission of MPDU without RTS/CTS

77 FIGURE 6.72 Transmission of MPDU with RTS/CTS

78 FIGURE 6.73 Point coordination frame transfer

79 FIGURE 6.74 IEEE physical layer

80 FIGURE 6.75 Frequency-hopping spread spectrum PLCP frame format

81 TABLE 6.5 Default lime parameters in IEEE frequency-hopping spread spectrum physical layer

82 FIGURE 6.76 Direct sequence spread spectrum using 11-chip Barker sequence

83 FIGURE 6.77 Direct sequence spread spectrum PLCP frame format

84 TABLE 6.6 Default time parameters in IEEE direct sequence spread spectrum physical layer

85 FIGURE 6.78 Infrared PLCP frame formal

86 TABLE 6.7 Default lime parameters in IEEE infrared physical layer

87 6.7 LAN BRIDGES FIGURE 6.79 A bridged LAN

88 FIGURE 6.80 Interconnection by a bridge

89 TABLE 6.8 Forwarding table (with no data)

90 FIGURE 6.81 Initial configuration

91 FIGURE 6.82 S1 sends a frame to S5

92 FIGURE 6.83 S3 sends a frame to S2

93 FIGURE 6.84 S4 sends a frame to S3

94 FIGURE 6.85 S2 sends a frame to S1

95 FIGURE 6.86 Sample topology

96 FIGURE 6.87 The corresponding spanning topology

97 FIGURE 6.88 Frame formal for source routing

98 FIGURE 6.89 LAN interconnection with source routing bridges

99 FIGURE 6.90 Routes followed by single-route broadcast frames

100 FIGURE 6.91 Routes followed by all-routes broadcast frames