Pawan Kumar Verma

Machine-to-Machine (M2M) communications

Machine-to-Machine (M2M) communication is a promising technology for next generation communication systems. This communication paradigm facilitates ubiquitous communications with full mechanical automation, where a large number of intelligent devices connected by wired/wireless links, interact with each other without direct human intervention. As a result, M2M communication finds applications in wide areas such as smart grids, e-healthcare, home area networks, intelligent transportation systems, environmental monitoring, smart cities, and industrial automation. However, distinctive features in M2M communications form different challenges from those in human-to-human communications. These challenges need to be addressed, or otherwise it is not easy for this paradigm to gain trust of people. To understand M2M communications deeply, this paper presents a comprehensive review of M2M communication technology in terms of its system model architecture proposed by different standards developing organizations. This mainly includes 3GPP, ETSI, and oneM2M. Further, we have investigated distinctive features of various M2M applications and their supporting attributes, the M2M data traffic and their characterization, various M2M standardization bodies and their unique tasks, and potential M2M communication challenges and their proposed state-of-the-art solutions, followed by future research directions.

A robust hybrid-MAC protocol for M2M communications

In M2M communications, there is a critical requirement of a robust MAC protocol to enable multiple M2M devices to access the channel. For this purpose, reservation or contention based MAC protocols can be used, but with multiple M2M devices, adaptability, and scalability become bottlenecks. Therefore, a frame based hybrid-MAC scheme, consisting of a CSMA-based contention period, and a TDMA-based transmission period has been proposed here. During contention period, the devices compete for the channel access. The successful devices during this period will strive to transmit data, using IEEE 802.11 DCF mechanism within each TDMA slot. The aim is to make sure that in case of TDMA clock synchronization failure, there is no communication failure between M2M devices. Extensive simulation results in ns-2 environment show that the proposed time frame scheme for hybrid-MAC protocol performs better than slotted-ALOHA and TDMA in terms of aggregate throughput and average end-to-end delay.

A novel hybrid medium access control protocol for inter-M2M communications

A scalable medium access control (MAC) protocol is crucial for machine-type devices to access the channel simultaneously in a machine-to-machine (M2M) network. There can be two types of scenarios in an M2M network. First, where the M2M devices communicate with the base station one-by-one, and second, where the M2M devices directly communicate with each other within a group or cluster without any human intervention (Inter-M2M communication). Considering the second type of scenario, the devices can use basic contention or reservation-based MAC protocols. But with such a large number of M2M devices, adaptability, and scalability become bottlenecks. Therefore, in this paper, we propose a novel scalable hybrid-MAC protocol, which combines the benefits of both contention-based and reservation-based medium access schemes. We assume that the contention and reservation portion of M2M devices is a frame structure, which mainly has two parts: contention interval (CI) and data transmission interval (DTI). The devices contend for the channel access during CI. After contention, the successful devices win time-slots and transmit data packets during DTI. In our proposed hybrid-MAC scheme, each M2M device is IEEE 802.11 DCF enabled, and within each time slot during DTI, the devices share data with each other. The analytical and simulation results show that the proposed hybrid-MAC protocol performs better than slotted-ALOHA, p-persistent CSMA, and TDMA in terms of aggregate throughput, average transmission delay, channel utility, and energy consumption.

A Novel Scalable Hybrid-MAC Protocol for Densely Deployed M2M Networks

In this paper, we propose a scalable hybrid-medium access control (MAC) protocol for inter-M2M communications, which combines the benefits of both contention-based and reservation-based medium access schemes. This protocol facilitates concurrent transmissions through spatial reuse. We assume that the contention and reservation portion of M2M devices is a frame structure, which is comprised of two sections: contention interval (CI) and transmission interval (TI). The CI duration follows p-persistent carrier sense multiple access (CSMA) mechanism, which allows M2M devices to contend for the transmission slots. After contention, only those devices, which have won time-slots, are allowed to transmit data packets during TI. In our proposed MAC scheme, the TI duration is basically a time division multiple access (TDMA) frame. Each M2M transmitter device and its corresponding one-hop distant receiver device communicate using MBAA-MAC protocol within each TDMA slot to facilitate concurrent transmissions, and to overcome the various limitations of TDMA mechanism. The simulation results demonstrate the effectiveness of the proposed hybrid-MAC protocol.

Throughput enhancement of a novel hybrid-MAC protocol for M2M networks

When the M2M devices communicate with each other within a group or cluster without any human intervention, this is called inter-M2M communications. Hence, there is a critical requirement of a scalable medium access control (MAC) protocol to enable multiple M2M devices to access the channel. For this purpose, contention or reservation-based MAC protocols can be used, but with multiple M2M devices, adaptability, and scalability become bottlenecks. Therefore, in this paper, we propose a novel hybrid-MAC protocol, which mainly consists of a contention interval (CI), and a data transmission interval (DTI). During CI, all the active M2M devices contend for the channel access. After contention, the successful devices win time-slots in DTI. The M2M devices are enabled with another proposed high throughput MAC (HT-MAC) protocol, and share data with each other within each time-slot during DTI. Simulation results show significant per time-slot throughput improvement as compared to IEEE 802.11 MAC protocol.