th services transmitted on fixed, landline networks. An all-IP packet infrastructure. www.TechnicalPDF.com Internet Protocol version 6 (IPv6) addressing, which has more addresses than IPv4. See Chapter 6, "The Internet," for information on IP addressing. See the section "Addressing Protocols" in Chapter 6 for information on IPv6 and IPv4. The ability to support mobile TV. Efficient use of spectrum. Worldwide roaming compatibility between mobile 4G devices. Internetworking refers to the fact that 4G devices can seamlessly be handed over between cell sites that use 3G and 4G protocols without transmission interruptions. See Figure 7-3 for an example of a handover between 3G and 4G networks. Handovers are the process that occurs when subscribers travel between networks that support different protocols. networks: handover Signaling Gateways transfer subscriber between 4G and 5G networks 4G Network 5G Network Billing,text messaging databases Signaling gateway Signaling gatev messaging Smartphone transmits device Figure 7-3 The handover between 3G and 4G networks. A number of manufacturers compete with one another to supply 4G and 5G network software and hardware. These include Ericsson, Huawei, Nokia, Samsung, Xiaomi, and ZTE. 4G LTE-Designed to Transmit Data and Voice in IP Packets 4G technology was developed with the goal of supporting high-speed broadband and video transmissions. It is the first mobile protocol designed primarily to transmit data. It supports voice, but only as IP within data packets. LTE has improved antennas, and faster chips in handsets and in radios in the network. The mobile core is the mobile carrier's data center. It is equipped with servers containing databases and software to control and monitor the network as well as providing connections to other networks. www.TechnicalPDF.com LTE is the 4G protocol adopted by carriers worldwide. Manufacturers produce a wide choice of devices for networks that use these air interfaces, because these networks represent a large pool of potential customers.