The Hybrid Fiber Coaxial HFC Network

Hfc Node Fiber Tail

The first networks to include a fiber node-type technology were built beginning in 1990. CATV networks today are built exclusively using HFC design and older networks are being retrofitted to receive the benefits of HFC. As a result, most CATV networks today are based on fiber node-based architecture, but they also include elements of the older coaxial networks. The HFC network design helps reduce many of the amplification and attenuation issues and other issues associated with all coaxial...

Signaling Links and Link Sets

Signaling links are physical connections between SS7 nodes and are responsible for the reliable transmission of SS7 signaling messages between those nodes, as shown in Figure 2-9. Signaling links can be configured so that they load share traffic over any or all of the links in a designated link set between signaling points. Even distribution of traffic is only achieved if there are several signaling links of the power 2 (2, 4, 8, and so on). Figure 2-9 Signaling Links Between SS7 Network Nodes...

Common Cable Plant Issues

As a CATV or cable modem signal is transmitted downstream through the branched cable topology, the signal becomes attenuated and weaker at each branching and with cable distance. What is initially a strong signal requires amplification to adequately reach the subscriber. Noise or interference in downstream frequencies that enters the cable system at some distance from the headend only affects customers past that point. It does not affect all subscribers, as it does not originate at the headend....

Service Profile Identifiers SPIDs and Telephone Numbers

Possibly the most important single piece of information for a BRI subscriber in the United States is the SPID. SPIDs identify the BRI circuit on the switch along with the circuit ID, and the services that the circuit has assigned to it. For each B channel assigned to the circuit, there is a SPID associated with it, and for each SPID there is an associated telephone number. When you look at the format of a SPID, it looks a lot like a regular telephone number with an added extension. The most...

Building Integrated Timing Supply BITS

BITS is a North American term that describes a building-centric timing system. Also referred to as a Synchronization Supply Unit (SSU), the BITS system efficiently manages the number of timing interfaces within a structure. Without something such as BITS SSU in place, you can feasibly have many different timing sources within the same building because of the number of synchronous links that the building might contain. BITS operates by providing the only ingress and egress external timing...