Jamil Y. Khan

Review Article: A comprehensive review of the application characteristics and traffic requirements of a smart grid communications network

A robust communication infrastructure is the touchstone of a smart grid that differentiates it from the conventional electrical grid by transforming it into an intelligent and adaptive energy delivery network. To cope with the rising penetration of renewable energy sources and expected widespread adoption of electric vehicles, the future smart grid needs to implement efficient monitoring and control technologies to improve its operational efficiency. However, the legacy communication infrastructures in the existing grid are quite insufficient, if not incapable of meeting the diverse communication requirements of the smart grid. Therefore, utilities from all over the world are now facing the key challenge of finding the most appropriate technology that can satisfy their future communication needs. In order to properly assess the vast landscape of available communication technologies, architectures and protocols, it is very important to acquire detailed knowledge about the current and prospective applications of the smart grid. With a view to addressing this critical issue, this paper offers an in depth review on the application characteristics and traffic requirements of several emerging smart grid applications and highlights some of the key research challenges present in this arena.

Performance evaluation of a Wireless Body Area sensor network for remote patient monitoring

In recent years, interests in the application of Wireless Body Area Network (WBAN) have grown considerably. A WBAN can be used to develop a patient monitoring system which offers flexibility and mobility to patients. Use of a WBAN will also allow the flexibility of setting up a remote monitoring system via either the internet or an intranet. For such medical systems it is very important that a WBAN can collect and transmit data reliably, and in a timely manner to the monitoring entity. In this paper we examine the performance of an IEEE802.15.4/Zigbee MAC based WBAN operating in different patient monitoring environment. We study the performance of a remote patient monitoring system using an OPNET based simulation model.

Wireless Body Area Network (WBAN) Design Techniques and Performance Evaluation

In recent years interest in the application of Wireless Body Area Network (WBAN) for patient monitoring applications has grown significantly. A WBAN can be used to develop patient monitoring systems which offer flexibility to medical staff and mobility to patients. Patients monitoring could involve a range of activities including data collection from various body sensors for storage and diagnosis, transmitting data to remote medical databases, and controlling medical appliances, etc. Also, WBANs could operate in an interconnected mode to enable remote patient monitoring using telehealth/e-health applications. A WBAN can also be used to monitor athletes’ performance and assist them in training activities. For such applications it is very important that a WBAN collects and transmits data reliably, and in a timely manner to a monitoring entity. In order to address these issues, this paper presents WBAN design techniques for medical applications. We examine the WBAN design issues with particular emphasis on the design of MAC protocols and power consumption profiles of WBAN. Some simulation results are presented to further illustrate the performances of various WBAN design techniques.

Wireless Body Sensor Network Using Medical Implant Band

A wireless body sensor network hardware has been designed and implemented based on MICS (Medical Implant Communication Service) band. The MICS band offers the advantage of miniaturized electronic devices that can either be used as an implanted node or as an external node. In this work, the prototype system uses temperature and pulse rate sensors on nodes. The sensor node can transmit data over the air to a remote central control unit (CCU) for further processing, monitoring and storage. The developed system offers medical staff to obtain patient’s physiological data on demand basis via the Internet. Some preliminary performance data is presented in the paper.

Monitoring of Physiological Parameters from Multiple Patients Using Wireless Sensor Network

This paper presents a wireless sensor network system that has the capability to monitor physiological parameters from multiple patient bodies. The system uses the Medical Implant Communication Service band between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patient’s physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

A Wireless Medical Monitoring Over a Heterogeneous Sensor Network

This paper presents a heterogeneous sensor network system that has the capability to monitor physiological parameters from multiple patient bodies by means of different communication standards. The system uses the recently opened medical band called MICS (medical implant communication service) between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the Internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patients physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested by incorporating temperature and pulse rate sensors on nodes. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

On optimal network selection in a dynamic multi-RAT environment

A significant challenge to enable multimedia service delivery in a dynamic multiple radio access technologies (multi-RAT) environment is the coordination of vertical handovers between different RATs. Cost function approach has been widely adopted to make vertical handover decision by ranking candidate networks. Although this mechanism can reflect accurately the change of network states and user requirements, it results in frequent, and often, unnecessary handovers which have detrimental impact on QoS, signaling load and system capacity. In this letter, we introduce a novel measurement-based network selection technique that provides a pragmatic way to acquire QoS information. In addition, it augments the handover decision of existing cost function approach, through handover initiation, to provide an optimal network selection outcome. OPNET simulations verify that the proposed technique can reduce unnecessary handovers considerably, improve overall QoS and system capacity.

Dynamic Access Network Selection with QoS Parameters Estimation: A Step Closer to ABC

Always best connected (ABC) services allows multi- mode mobile terminals to stay connected to the best available networks, at anytime according to user preferences. One of the key aspects in realizing such ABC service is mainly attributed to an effective and dynamic access network selection process. However, most of the previous works consider the access network selection process as a static optimization problem which fails to address the dynamic QoS conditions intrinsic in wireless networks. One of the main challenges remains as no efficient way in obtaining dynamic QoS parameters such as packet delay, packet loss and jitter. In this paper, we proposed a novel dynamic access network selection algorithm capable of adapting to prevailing network conditions. Our algorithm is a dual stage estimation process where network selection performed using sequential Bayesian estimation relies on dynamic QoS parameters estimated through bootstrap approximation. Simulations demonstrate the effectiveness of our proposed algorithm which outperforms static optimization approach in a highly efficient manner.

Power Efficient Ultra Wide Band Based Wireless Body Area Networks with Narrowband Feedback Path

The basic requirement of wireless healthcare monitoring systems is to send physiological signals acquired from implantable or on-body sensor nodes to a remote location. Low-power consumption is required for wireless healthcare monitoring systems since most medical sensor nodes are battery powered. The emergence of new technologies in measuring physiological signals has increased the demand for high data rate transmission systems. Ultra-wide band (UWB) is a suitable wireless technology to achieve high data rates while keeping power consumption and form factors small. Although UWB transmitters are designed based on simple techniques, UWB receivers require complex hardware and consume comparatively higher power. In order to achieve reliable low power two-way communication, a sensor node can be constructed using a UWB transmitter and a narrow band receiver. This paper proposes a new medium access control (MAC) protocol based on a dual-band physical layer technology. Co-simulation models based on MATLAB and OPNET have been developed to analyze the performance of the proposed MAC protocol. We analyzed the performance of the MAC protocol for a realistic scenario where both implantable and wearable sensor nodes are involved in the data transmission. Priority-based packet transmission techniques have been used in the MAC protocol to serve different sensors according to their QoS requirements. Analysis is done with regard to important network parameters, such as packet loss ratio, packet delay, percentage throughput, and power consumption.

Key performance aspects of an LTE FDD based Smart Grid communications network

The Smart Grid will enable a new era of electricity generation, transmission, distribution and consumption driven by efficiency, reliability, flexibility and environmental concerns. A key component of the Smart Grid is a communications infrastructure for data acquisition, monitoring, control and protection. In this paper, we evaluate the key performance aspects of an LTE Release 8 FDD network as the wide area communications network for Smart Grid applications. We develop analytical results for latency and channel utilization and discuss the implications for Smart Grid traffic sources, particularly the fact that system capacity is likely to be control channel limited. We also develop an OPNET based discrete event simulation model for a PMU based fault monitoring system using LTE FDD as its communication medium and use it to validate the analytical findings. In particular, we demonstrate how uplink data plane latencies of less than 10ms can only be achieved using small application layer packets. These findings can be used to understand how to best deploy an LTE FDD network in a Smart Grid environment and also in the development of new radio resource management algorithms that are tailored specifically to Smart Grid traffic sources.