Elements of a wireless network base station typically connected to wired network relay-responsible for sending packets between network wired network and infrastructure wireless host(s)in its area” ·eg,cell towers,. 802.I I access points Wireless and Mobile Networks 7-6
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 network infrastructure Wireless and Mobile Networks 7-6
Elements of a wireless network wireless link一) typically used to connect mobile(s)to base station also used as backbone link multiple access protocol network coordinates link access infrastructure ■various data rates, transmission distance Wireless and Mobile Networks 7-7
wireless link ▪ typically used to connect mobile(s) to base station ▪ also used as backbone link ▪ multiple access protocol coordinates link access ▪ various data rates, transmission distance Elements of a wireless network network infrastructure Wireless and Mobile Networks 7-7
Characteristics of selected wireless links 1300 802.11ac 450 802.11n 54 802.11a,g 802.11a,g point-to-point 5-11 802.11b 4G:LTWE WIMAX 4 3G:UMTS/WCDMA-HSPDA,CDMA2000-1xEVDO 邕 1 802.15 ejea 384 2.5G:UMTS/WCDMA,CDMA2000 .056 2G:IS-95,CDMA,GSM Indoor Outdoor Mid-range Long-range 10-30m 50-200m outdoor outdoor 200m-4Km 5Km-20 Km Wireless and Mobile Networks 7-8
Characteristics of selected wireless links Indoor 10-30m Outdoor 50-200m Mid-range outdoor 200m – 4 Km Long-range outdoor 5Km – 20 Km .056 .384 1 4 5-11 54 2G: IS-95, CDMA, GSM 2.5G: UMTS/WCDMA, CDMA2000 802.15 802.11b 802.11a,g 3G: UMTS/WCDMA-HSPDA, CDMA2000-1xEVDO 4G: LTWE WIMAX 802.11a,g point-to-point 450 802.11n Data rate (Mbps) Wireless and Mobile Networks 7-8 1300 802.11 ac
Elements of a wireless network infrastructure mode base station connects mobiles into wired network handoff:mobile changes network base station providing infrastructure connection into wired network Wireless and Mobile Networks 7-9
infrastructure mode ▪ base station connects mobiles into wired network ▪ handoff: mobile changes base station providing connection into wired network Elements of a wireless network network infrastructure Wireless and Mobile Networks 7-9
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
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 Elements of a wireless network Wireless and Mobile Networks 7-10