《计算机网络 Computer Networking》课程PPT教学课件（A Top Down Approach，8th edition）Chapter 7 Wireless and Mobile Networks

Chapter 7 James F.Kurose I Keith W.Ross Wireless and Mobile Networks A note on the use of these PowerPoint slides: We're making these slides freely available to all(faculty,students, readers).They're in PowerPoint form so you see the animations;and can add,modify,and delete slides (including this one)and slide content to suit your needs.They obviously represent a lot of work on our part. COMPUTER In return for use,we only ask the following: NETWORKING If you use these slides(e.g.,in a class)that you mention their A TOP-DOWN APPROACH source(after all,we'd like people to use our book!) tghthtdtion If you post any slides on a www site,that you note that they are adapted from(or perhaps identical to)our slides,and note our copyright of this material. Computer Networking:A For a revision history,see the slide note for this page. Top-Down Approach Thanks and enjoy!JFK/KWR 8th edition All material copyright 1996-2020 Jim Kurose,Keith Ross J.F Kurose and K.W.Ross,All Rights Reserved Pearson,2020

Computer Networking: A Top-Down Approach 8 th edition Jim Kurose, Keith Ross Pearson, 2020 Chapter 7 Wireless and Mobile Networks A note on the use of these PowerPoint slides: We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you see the animations; and can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following: ▪ If you use these slides (e.g., in a class) that you mention their source (after all, we’d like people to use our book!) ▪ If you post any slides on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material. For a revision history, see the slide note for this page. Thanks and enjoy! JFK/KWR All material copyright 1996-2020 J.F Kurose and K.W. Ross, All Rights Reserved

Wireless and Mobile Networks:context more wireless(mobile)phone subscribers than fixed (wired)phone subscribers (10-to-1 in 2019)! more mobile-broadband-connected devices than fixed-broadband- connected devices devices(5-1 in 2019)! 4G/5G cellular networks now embracing Internet protocol stack, including SDN two important(but different)challenges wireless:communication over wireless link mobility:handling the mobile user who changes point of attachment to network Wireless and Mobile Networks:7-2

Wireless and Mobile Networks: context Wireless and Mobile Networks: 7-2 ▪ more wireless (mobile) phone subscribers than fixed (wired) phone subscribers (10-to-1 in 2019)! ▪ more mobile-broadband-connected devices than fixed-broadband￾connected devices devices (5-1 in 2019)! • 4G/5G cellular networks now embracing Internet protocol stack, including SDN ▪ two important (but different) challenges • wireless: communication over wireless link • mobility: handling the mobile user who changes point of attachment to network

Chapter 7 outline Introduction Wireless Mobility -Wireless Links and network Mobility management:principles characteristics Mobility management:practice WiFi:802.11 wireless LANs ·4G/5 G networks Cellular networks:4G and 5G ·Mobile IP Mobility:impact on higher-layer protocols Wireless and Mobile Networks:7-3

Chapter 7 outline ▪ Introduction Wireless ▪ Wireless Links and network characteristics ▪ WiFi: 802.11 wireless LANs ▪ Cellular networks: 4G and 5G Mobility ▪ Mobility management: principles ▪ Mobility management: practice • 4G/5G networks • Mobile IP ▪ Mobility: impact on higher-layer protocols Wireless and Mobile Networks: 7- 3

Elements of a wireless network wired network infrastructure Wireless and Mobile Networks:7-4

Elements of a wireless network Wireless and Mobile Networks: 7- 4 wired network infrastructure

Elements of a wireless network wireless hosts laptop,smartphone,loT 。run applications may be stationary(non-mobile)or mobile wired network wireless does not always mean mobility! infrastructure Wireless and Mobile Networks:7-5

Elements of a wireless network Wireless and Mobile Networks: 7- 5 wired network infrastructure wireless hosts ▪ laptop, smartphone, IoT ▪ run applications ▪ may be stationary (non-mobile) or mobile • wireless does not always mean mobility!

Elements of a wireless network base station 角 typically connected to wired network relay-responsible for sending packets between wired network and wireless wired network host(s)in its“area” infrastructure e.g.,cell towers,802.11 access points Wireless and Mobile Networks:7-6

Elements of a wireless network Wireless and Mobile Networks: 7- 6 wired network infrastructure base station ▪ typically connected to wired network ▪ relay - responsible for sending packets between wired network and wireless host(s) in its “area” • e.g., cell towers, 802.11 access points

Elements of a wireless network wireless link 《》 typically used to connect mobile(s)to base station,also used as backbone link multiple access protocol coordinates link access wired network various transmission rates and distances, infrastructure frequency bands Wireless and Mobile Networks:7-7

Elements of a wireless network Wireless and Mobile Networks: 7- 7 wired network infrastructure wireless link ▪ typically used to connect mobile(s) to base station, also used as backbone link ▪ multiple access protocol coordinates link access ▪ various transmission rates and distances, frequency bands

Characteristics of selected wireless links 14 Gbps 802.11ax 10 Gbps 5G 3.5 Gbps 802.11ac 802.11af,ah 600 Mbps 802.11n 4G LTE 54 Mbps 802.11g 11 Mbps 802.11b 2 Mbps Bluetooth Indoor Outdoor Midrange Long range outdoor outdoor 10-30m 50-200m 200m-4Km 4Km-15Km Wireless and Mobile Networks:7-8

Characteristics of selected wireless links Wireless and Mobile Networks: 7- 8 Indoor Outdoor Midrange outdoor Long range outdoor 10-30m 50-200m 200m-4Km 4Km-15Km 2 Mbps 4G LTE 802.11ac 802.11n 802.11g 802.11b 3.5 Gbps 600 Mbps 54 Mbps 11 Mbps Bluetooth 14 Gbps 802.11ax 10 Gbps 5G 802.11 af,ah

Elements of a wireless network infrastructure mode base station connects mobiles into wired network handoff:mobile changes base station wired network providing connection into wired infrastructure network Wireless and Mobile Networks:7-9

Elements of a wireless network Wireless and Mobile Networks: 7- 9 wired network infrastructure infrastructure mode ▪ base station connects mobiles into wired network ▪ handoff: mobile changes base station providing connection into wired network

Elements of a wireless network ad hoc mode ■no base stations nodes can only transmit to other nodes within link coverage nodes organize themselves into a network:route among themselves Wireless and Mobile Networks:7-10

Elements of a wireless network Wireless and Mobile Networks: 7- 10 ad hoc mode ▪ no base stations ▪ nodes can only transmit to other nodes within link coverage ▪ nodes organize themselves into a network: route among themselves