With the widespread of different specialized networking technologies in the context of consumer telecommunications, industrial automation and the SmartGrid, Heterogeneous Network Infrastructures are becoming a concept that network administrators need to understand well and be prepared for. This article provides as short overview of the concept of Heterogeneous Networks and what are the predicted issues that need to be proactively dealt with.
Heterogeneous network infrastructures are the result of deploying different networking technologies in the same context (Enterprise, Factory, and Building.) in order to fulfill different communication needs. The resulting infrastructure supports the information system by providing means for application end-points to communicate with each other in a reliable and secure manner.
A generalized conceptual model for heterogeneous network infrastructures is depicted in the figure above. According to the figure, a HNI is composed of several sub-systems that each has its separate management system. End to end applications using the HNI involve several sub-systems along their data path.
The figure below illustrates the trend in integrating various networking technologies in the context of industrial automation.
As it can be seen in the figure above, the automation industry started by integrating a reliable (real-time) version of Ethernet in the early 2000's, then gradually, more technologies have been adopted such as WiFi and satellite communication, mainly for business operations. The recent trend is the adoption of wireless technologies for production as well as for business operations. This is being carried out now by the integration of new standards such as WiFi mesh, ISA100 and WirelessHART. It is planned that technologies such as WiMAX become part of the typical plant infrastructure in the near future. In the mid-term to long-term future, it is expected that more technologies will be developed and integrated to address shortcomings of current technologies and to meet future needs.
Recently, the automation industry started to realize the complexity issues introduced by such trend. The concept of heterogeneous network infrastructures although provides very valuable flexibility and improvements in efficiency, is suspected to introduce a non negligible management overhead that needs to be addressed.
Several challenges may arise from the disparity of technologies used to manage and operate heterogeneous network infrastructures. These challenges may be categorized as follows:
The efficiency in terms of operating cost and execution delays is an issue in heterogeneous network infrastructures due to the fact that different networking technologies require separate staff trained for each of these technologies. The increase in human resource requirements constitutes a cost burden. With regard to execution time also, since different technologies require different tools and different staff, the execution of infrastructure-wide operations (such as capacity planning, and policy management) require manual intervention and human interactions (staff meeting from different teams) to complete the necessary tasks. All this contributes to delays and time efficiency issues when executing infrastructure-wide operations.
When the heterogeneous infrastructure is in place, the exploitation and management of the available resources needs to be flexible enough to meet different requirements of the various applications that will use the infrastructure. For example, in quality-sensitive services, there is need to dynamically manage quality of service in a deterministic manner in order to meet severe QoS requirements. The same applies for security, provisioning operations and monitoring. The challenge resides in the fact that since the sub-systems that make the heterogeneous network infrastructure use different network management technologies, it is not easy to dynamically perform network management operations across several sub-systems.
Most of industry players and customers agree that there is need for new solutions to the efficiency and effectiveness of management operations in next generation heterogeneous network infrastructures. Such solutions would allow organizations that deploy Heterogeneous Network Infrastructures (HNIs) to reduce maintenance and operating costs while ensuring optimal utilization of the its infrastructure.
The type of solutions that would best meed these needs would include two main components: