Research via SCTE’s Energy 2020 Program indicates about 70 to 80 percent of participating cable operators’ energy footprints reside in Edge Facilities and Access Networks. Uniformly capturing how much power is consumed by these two domains is vital to measuring energy-efficiency improvements; so, earlier this summer, SCTE published two essential metrics standards.
SCTE 211 addresses Access Networks, which include all active and passive equipment between the headend or hub and the demarcation point at the user premises (i.e., in a nutshell, the outside plant). Three key items are defined:
- Energy per consumed bit (EPCB)—EPCB shall be defined as “kilowatt-hours per terabyte (kWh/TB).”
- Common procedure for defining the bitrate of consumed broadcast channels—For each type of broadcast service, determine the average number of viewed channels across the measurement time period and calculate the bytes transmitted during that time period as: Bytes consumed = bit rate * # of viewed channels * 1/8 bit/byte * time in seconds.
- Consumed bits in downstream and upstream flows of data over the access network—In the downstream (DS), a consumed bit is a bit of information that is used by at least one user or device connected to the access network (AN). All data or telephony bits delivered to a user or device are defined as consumed. All video on demand (VOD) or switched digital video (SDV) bits are defined as consumed. Broadcast (BC) video bits are only defined as consumed if at least one CPE device connected to the AN is either displaying or recording the video bits. In the upstream (US), all bits are defined as consumed.
Thousands of facilities exist at the edge of the service delivery network. SCTE 213 addresses the metrics to measure energy performance of these sites. Three key items are defined here as well:
- Functional energy productivity metric based on subscriber count as total number of critical facility subscribers by total critical facility power.
- Functional energy productivity metric based on data throughput as total critical facility data throughput by total critical facility power.
- Power usage effectiveness (PUE) as a quick structured approach for examining facilities by plotting energy performance on a grid as compared to other facilities.
In tandem, SCTE 211 and 213 provide the foundation for measuring the industry’s energy management success, and SCTE is on the verge of reporting the industry’s first official baseline from the initial data capture of participating operators.