Transforming Communication Infrastructure by mThink, May 23, 2005 For a long time the standard point-to-point analog line to a substation was all that was needed in the grid of the past. It worked well for many years and by default kept data requirements simple and minimized application integration. If a new data requirement was warranted, such as a dial-up circuit for a C&I meter, one would just add another phone line, and communication costs increased. Upon further advances in technology in equipment and applications, a spaghetti factory of dedicated circuits was installed into silos of technology at the substation. The communication and maintenance costs for the legacy-dedicated circuits provide little integration and no foundation for future requirements. This architecture hampers the use of new technology which is unable to leverage the existing network platform and becomes a budgetary hurdle for implementation of new practices. It is also a ticking time bomb of availability as communication providers eliminate analog circuits and continually increase the recurring costs. The substation is rapidly becoming a distinct network of information not limited to just operations. Applications and employees need real-time connectivity to the data assets for constant evaluation and maintenance. Resisting change and maintaining the status quo is quickly becoming the wrong answer for distribution companies. A strategic investment in network architecture will enable the use of information and provide a lasting benefit for the foreseeable future. Considerations Any change or investment in advancement of infrastructure must improve service levels and network performance while minimizing the regulatory pressures on price. Most distribution companies rejections to change network architecture have been for two reasons. Cost is the first. The second has been the resistance to change. Not updating the network architecture may result in stable prices, but is likely to increase service interruptions. Any change must be price sensitive and provide real return on investment. It has to address the concerns of operations, make use of existing capital infrastructure and create a secure environment and meet new regulatory standards. A major consideration for the chosen network platform is to support multiple applications and data assets within the substation and the enterprise. The use of new technology will assist in a positive ROI scenario, enabling better asset management and utilization techniques. Figure 1 lists several components and use cases possible on the network. There is only one real choice of platform that effectively meets considerations outlined above and that is a TCP/IP network. Implementation of a TCP/IP network will not only be cost effective but also provide far greater functionality to distribution companies than todays legacy network. For instance, with the migration of SCADA and control traffic to an IP-based solution, single use and high-cost analog circuits can be decommissioned. The data can now be delivered over a single digital circuit. With an IP-controlled network, engineers will now be able to monitor and make changes to the site remotely, reducing the expense and delay involved in making physical site visits. An IP-based solution enables redundancies to be put in place that cannot be achieved with todays analog network. For sites where connectivity is imperative, an IP solution provides the ability to dial up over a backup circuit or reroute traffic to a secondary data center in the case of a communications failure with the primary data center. It can also allow duplication of the information generated so multiple data centers can simultaneously monitor the networks. The IP solution will also allow the control of SCADA information to be encrypted before it is sent across the network, providing an additional layer of operational security and meeting potential future regulatory requirements. Once the IP migration is complete, significant cost savings will be achieved with the decommissioning of legacy infrastructure required by todays network. Network Considerations There are many choices of TCP/IP platforms to evaluate for the communication infrastructure. Most commonly used are satellite, dedicated fiber, frame relay, cellular, radio and PSTN (public switched telephone network). Each has their advantages and disadvantages and all can be a part of the total solution. Satellite networks are easy to integrate and are very portable for installation but the relative data throughput and cost are unattractive. Also, they have a delay in transmission that not all applications can handle, especially older equipment. Cellular is also easy to install but has coverage problems, limiting network availability. This would warrant it for only redundancy or noncritical data assets. These assets would include AMR, C&I metering and remote diagnostics. One must also be careful to secure a cellular network with proper components, as typically they are open to the Internet. With proper security it is a credible low cost platform for redundancy implementation. The recurring cost is associated with bandwidth utilization and can run as low as a few dollars per month for service. Only when a critical failure occurs in the primary network would cellular network be utilized. The portability and ease of installation makes the total cost of ownership of cellular the primary choice for redundancy. Dedicated fiber fits all the requirements but is very expensive to install and maintain once in place. Radio networks will work for most applications but throughput is a major concern as well as interference from other sources. Only a few types of radio networks in the non-licensed spectrum will support TCP/IP. PSTN networks will work for low bandwidth applications similar to cellular only the costs are higher. It would be a good choice when cellular is not available. Frame relay is the best choice for the primary network. It has the high availability required for mission-critical throughput performance desired for applications. Frame relay is a copper connection from the communication providers local point of presence and is purchased in different segments as required per substation environment. An advantage is when your bandwidth demand exceeds the current segment throughput over the same copper connection can ratchet up as needed from the service provider be it a 56Kbps connection up to a full T-1. A multi-protocol label switching (MPLS) solution as the core of the network is recommended and connecting all of the circuits into an MPLS cloud. The MPLS functionality rides on top of the basic TCP/IP network structure, providing advanced features that have real relevance in the utility industry. Benefits of an MPLS network are: Any-to-any connectivity; IP convergence; Redundancy and availability; High degree of bandwidth scalability; and Performance. MPLS will provide a core network that is more resilient because, unlike the current ATM clouds and other platforms, MPLS has the ability to route around failures within the service providers network. Therefore, if the service provider is experiencing congestion or hardware failures within its network, one will not lose connectivity between its sites. The MPLS network has the intelligence to find a different path between the endpoints and will automatically reroute the traffic around the network failure. Service level agreements are obtainable from the service providers covering availability and performance. MPLS provides the ability for any site connected to the cloud to communicate directly with any other site connected to the cloud. By removing the aggregation points within the network, any-to-any connectivity helps support future projects such as the consolidation of servers or call centers into a centralized facility. Any-to-any connectivity also supports the migration of analog voice to a voice over IP solution in the future. The removal of the dependencies on aggregation sites enables shorter circuits to be installed and the future removal of legacy communication infrastructure. Shorter circuits are less expensive and the removal of the legacy links will greatly reduce operating and maintenance expenses and reduce future capital expenditures. MPLS also allows prioritization of data and configuration within each network endpoint. This is critical to the operation of the communication infrastructure within the utility marketplace. The classification of each data component enables the end user to reduce the segment size of the pipe and allocate portions of the segment for critical applications. Examples of the classification are in Figure 2. Class A data is considered the highest priority for real-time control and operations. Class B is the next level and so on. The benefit of classification is that each class is configurable for bandwidth utilization with a standard and maximum. This allows the higher classes to acquire bandwidth as needed. This means the frame relay network can be focused in avalanche mode for applications critical for operations and services. During steady-state or non-avalanche mode, a larger percentage of the bandwidth is available for the lower classes to operate but is limited in critical situations. Security New regulatory standards are requiring that all routable protocols linked to critical assets be cyber secure, preventing unauthorized access. Also, physical access to the critical assets in the substation is to be logged and monitored during operation, adding another data requirement to the network architecture. Cyber security is achieved through industry-standard techniques such as secure shell and IPSec. This will provide both authentication and encryption of the required network connections within the substation. The physical requirement can be accomplished through several techniques such as cameras, RFID or bar scanners with off-the-shelf applications. The application provides real-time notification and logs the identification of any personnel entering each critical asset. Benefits There are several tangible benefits for distribution companies that implement a TCP/IP communication platform. Some but not all benefits can be: Operational Enhanced information allows faster and cheaper recovery from faults. Remote asset monitoring allows faults to be anticipated and avoided. Real-time information provides detailed data on faults, keeping blackouts as short as possible. Higher availability of data in network performance and redundancy can increase service levels. Reduces outages and network downtime. Meets new regulatory requirements for cyber security of critical assets. Financial Lower communication costs achievable. Load balancing of demand to better manage and reduce peaks. Custom analytics enhances asset life prediction and network planning. Provides low cost availability of data to back-end applications. Responds to opportunities derived from deregulation. Remote asset monitoring supports just in time replacement of failing assets. Optimizes usage of aging network infrastructure. Conclusion Utilities require a strategic investment in communication infrastructure to provide a platform that enables business units to operate and grow effectively within the enterprise. The legacy approach to build point solutions for communication needs is a failure looking forward. An investment in a TCP/IP platform, such as an MPLS frame relay network, is the only cost-effective approach to remain competitive in an industry ready to enable growth. Filed under: White Papers Tagged under: Utilities