* SDH (Synchronous Digital Hierarchy) is a higher-level multiplexing standard: It bundles multiple lower-level signals, like E1s, into larger capacity streams.
* SDH radio systems have varying capacities: The number of E1s that can be carried depends entirely on the specific SDH radio equipment and its configuration.
* Different SDH levels: SDH has different levels (STM-1, STM-4, STM-16, etc.) each with a different total bandwidth. The number of E1s you can multiplex within an SDH radio is determined by the chosen SDH level.
Here's how to determine the number of E1s:
1. Identify the SDH level: Check the specifications of your SDH radio equipment. It will indicate the supported STM level.
2. Calculate the total capacity: Each STM level has a fixed bandwidth (e.g., STM-1 is 155.52 Mbps).
3. Determine the E1 equivalent: One E1 carries 2.048 Mbps. Divide the total capacity of the SDH level by the E1 bandwidth to get the number of E1s you can fit.
Example:
* If your SDH radio is STM-1, it has a capacity of 155.52 Mbps.
* 155.52 Mbps / 2.048 Mbps/E1 = 76 E1s (approximately)
In summary, there's no fixed number of E1s in an SDH radio. It depends on the specific SDH level used and the equipment's capacity.