Dedicated wavelengths are used in 5G cellular networks to connect small antennas to each other. See Chapter for information on 5G cellular service. T1 and T3: Services Largely Replaced by Higher-Capacity Broadband T1 service is a digital broadband technology that utilizes a multiplexing scheme, which enables one circuit to carry 24 voice, video, or data channels. The entire circuit runs at 1.54Mbps. T3 is also able to carry a variety of traffic types but operates at 44Mbps. E1 and E3 are the multiplexed services used in Europe. Ethernet, where it's available, is largely replacing T1 and T3 because it provides a more scalable solution and is not limited to 44Mbps. In the United States, AT&T and Verizon no longer support T1 and T3. They are gradually replacing them with Carrier Gigabit Ethernet, which is not limited to 44Mbps and has more flexible speeds, and is less costly for telephone companies to support. TDM Shortcomings-Wasted Capacity, Higher- Support Costs Each device that communicates over a T1 or T3 line is assigned a time slot. If there are eight telephones or www.TechnicalPDF.com computers contending for any of the above channels, a time slot is saved for each telephone and computer for the duration of the particular telephone call or data session. Telephone or computer device 1 might be assigned time slot A; telephone or computer 2, time slot B; and SO forth. During pauses in voice conversations, the slot is not assigned to another computer. The assigned time slot is transmitted without any information. These idle time slots result in wasted capacity. For this reason and because TDM capacity is limited to 44Mbps, TDM is not efficient for the higher capacities required for cloud and broadband services. In a network with millions of time slots, empty time slots result in many idle time slots and wasted bandwidth. T1 and T3 - Costly to Support and Install In addition to its lack of flexibility and capacity, T1/T3 service is costly for telephone companies to support. This is mainly due to the cost of equip