Reuse is key to limiting both CAPEX and OPEX in the backhaul network. Aviat alone has over 18K links of MW radio installed in MC applications in the US – representing roughly $1.5B of investment in equipment/services. Aviat studies show that reuse of this installed equipment can reduce or eliminate tower climbs (reusing installed antennas/wg/etc) with ~30-50% savings over greenfield installations. Also if we look at OPEX contributions for commercial tower/rooftops siting model, we see that ~50% of the OPEX cost is for infrastructure rental (tower site and ground site). If existing S&L facilities/infrastructure is utilized, the site rental portion of OPEX would go to zero. We should also note that MW TCO is much less that Fiber TCO over a 10 year period. The savings are different depending on the build vs. lease fiber model but both are much larger than 50% over the 10 year period.
Backhaul – mainly fiber backhaul, one of the significant contributors to these outages. Aviat provided many temp links to bridge the gap until fiber services could be restored…one might think the temporary MW perhaps should be considered permanent in some cases as backup to fiber.We believe there were very few if any outages in the Public Safety network (dominated by MW BH)They do not really suffer from the same failure mechanisms…to a significant extent they complement each other….flooding, winds blowing down trees and backhoes are failures for fiber and are occur typically when we need PS services the most. MW systems are typically designed to handle outages with little or no implications to the entire network (typically outages of seconds or minutes) and catastrophic failures are extremely rare. Key components of reliability: 1. Radio reliability – certifications such as NEBS, GR-63-CORE, GR-1089-CORE, water ingress, humidity, 70-100 year MTBF. 2. Radio and network design – use of rings, protection configurations, No Single Point of Failuer, use of high wind support struts for antennas3. Intrusion Security – FIPS 140-24. Proper implementation – antenna and strut attachment, grounding, lightning protection (estimated 2/3 of failures in MW systems are due to poor or improper installations)5. Monitoring and maintenance
Theoretical capacity per sector for 2x10Mhz is 43Mbps down/14.4Mbps up for close single user. Far from the BTS the capacity is 14Mbps down/4.8Mbps up. Adding more users further degrades the total capacity per sector…meaning that a good figure for planning backhaul is about 100Mbps for a 3 sectored configuration. This includes no efficiencies from over subscription, may be appropriate to use in the calculations. We know that LTE capacity will continue growing with Advanced LTE, so capacity enhancement continues to be a key R&D focus for the industry and we will continue seeing new technology advancements enabling even higher capacity. MW radio effective capacity grows in many ways: 2 combined channels, use of V/H polarizations on the same path, Adaptive Modulation, even compression techniques. We do not believe that for single hop or for multi-hop rings, the capacity of MW will be exceeded.
MW has supported the PS community for >50years. Over the last few years , MW has supported the rapid roll out of LTE for commercial networks. MW can be deployed in most cases faster than new fiber. The MW industry has a strong ecosystem of regional companies that support the installed base of PS radios, as well as vendor led support throughout the US. In addition, the Utilities industry utilizes a tremendous amount of MW in their networks and they are typically self supporting in terms of MW network maintenance. Thus the combined industries has a huge installed base of skilled workers available to support/maintain the upcoming MW deployments for the NW PS BB network.
In closing, we all want to ensure the NW PS BB network allows our PS professionals to respond to the next major emergency that our country faces. And as our very good friends in the PS community constantly remind us, keep me off the 6 Oclock news!
Building the FirstNet Nationwide Network: Architecture Solutions