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