Mobile Backhaul

4.3 Physical Interfaces

4.3.1 High Data Rates

Theoretical air interface single user peak rates for selected radio technologies in downlink (DL) and uplink (UL) is shown in Figure 4.6 together with the Ethernet port capacities. This illustrates one of the key benefits of an Ethernet port, high capacity.

Figure 4.6 Peak rates of 3GPP air interfaces vs Ethernet. *) Peak rate of air interface is the theoretical maximum peak rate per single user. Note: HSPA+ evolution not included.

Figure 4.7 Ethernet on the first mile BTS access.

The above shows the capability of Ethernet, e.g. as a single port in an eNodeB to scale capacity-wise, and match the peak rates of the air interface. The other benefit of Ethernet is low cost. Due to the widespread high volume usage of Ethernet ports, the cost per bit in routers and switches is typically lower with Ethernet compared to other ports, such as Packet over Sonet, or IP over PPP over E1/T1s. Due to these reasons, Ethernet is often the first alternative for the physical interface port, when connecting IP based BTSs to the packet mobile backhaul.

4.3.2 Ethernet Ports

IEEE standards include data rates for 10 Mbit/s (10 BaseT), 100 Mbit/s (FastEthernet), 1 Gbit/s (Gigabit Ethernet) and 10 Gbit/s [12]. 40 Gbit/s and 100 Gbit/s standards have also been ...