Point-to-MultiPoint Data
Point-to-multipoint radios are versatile low cost "last mile" transport solution that if properly designed can provide reliable data transport for a wide range of substation and field data backhaul needs. Point to Multipoint may be suitable for some IP to such as Substation applications as well as field backhaul applications. Common applications include SCADA, Distribution Automation (DA), and AMI. Unlike point to point solutions which provide dedicated bandwidth, point to multipoint offer shared bandwidth which is divided among several remote radio sites.
The method that bandwidth is shared varies between products but is important to understand when designing a system. Some types of point to multipoint radio systems transport Ethernet IP and serial while others are strictly serial. Radios are also available in a variety of licensed and unlicensed bands and data capabilities.
Licensed products are typically narrow band and low capacity, only suitable for low throughput applications. Licensed product benefit from having dedicated channel use and protection from the FCC if interference occurs from a known source. Some UHF licensed radio products can be used in non-line of sight conditions and will have superior coverage compared with unlicensed products. Common Licensed for utilities and cooperatives include: 150MHz, 220MHz, 450MHz, 900MHz. Most of these products are typically narrow band and constrained to 25kHz or 12.5kHz channels, and therefore low shared capacity. A few license 220MHz products are capable of operating on aggregated (adjacent) 220MHz channels which are 50kHz or wider. These aggregated products are capable of providing more capacity than typical narrow band licensed products. Aggregated licensed products may be suitable for transport of Ethernet IP applications whereas narrowband products will only have very limited IP capacity if it is available at all.
Unlicensed products are capable of broadband speeds but are sometimes negatively impacted by interference. Unlicensed bands include:
900MHz, 2.4GHz and 5.8GHz, 3.65GHz. These products typically have a total over the air capacity of 500kbps to 1Mbps with a few products that are capable of more than 1 Mbps over the air. A major limitation of all unclicensed products is that most unlicensed products available today will require line of sight or "near" line of sight over longer distances to ensure reliable communications.
Power System Engineering, Inc. (PSE) uses a proven process to assess feasibility, procure, and design point to multipoint systems.
PSE's understanding of capabilities of the leading communication vendors and the cost and functionality trade-offs between the different types of point to multipoint systems is how we have developed a proven track record for successful completion of these projects.
When the decision is made to move forward on evaluation of a new microwave transport system, PSE can support the utility by:
- Needs Assessment:
- Assessing business, functional, and technical requirements.
- Determining required transport traffic type. Serial or IP and the radios that offer the most robust performance for each.
- Determining transport capacity requirements by means for high level approximation or measurement and analysis of data requirements of existing applications.
- Establishing reliability and redundancy requirements.
- Technology & Financial Planning:
- Developing a backbone technology plan, including determining if a licensed, unlicensed, or a combination of licensed and unlicensed microwave network will be the best approach.
- Completing feasibility and business cases.
- System Design:
- Researching available tower locations, leased or owned, providing on-site assessments, and assisting with the site procurement or leasing process.
- Conducting path reliability studies and coordinating line-of-site path surveys.
- Determining the appropriate system protocol.
- Contract, Licensing & Project Management:
- Assisting or administering the vendor contract management process, including request for proposals (RFPs) that provide favorable terms and conditions for our clients.
- Facilitating spectrum and Federal Communications Commission (FCC) licensee planning and administration.
- Offering an experienced and competent project and program management team.
- System Integration:
- Providing project management of the system deployment.
- Facilitating third-party verification of the System Acceptance Tests (SAT)
- Offering final system integration of the applications to the new point-to-multipoint system.
PSE has established key repeatable business processes in helping electrical utilities determine their technology needs, selecting the most appropriate vendor and completing the contract and financial steps while migrating to deployment and cutover. These proven processes and experiences will deliver value, while keeping the system capital costs as low as possible.
