Human-type Communication Research Articles

Cellular machine-type comm unications: physical challenges and solutions

Cellular communication technologies are developed mainly for human-type communications, while enabling machine-type communication (MTC) with cellular networks (e.g., 3GPP LTE) not only improves the accessibility, availability, and reliability of an MTC network, but also has the potential to further drive down the operation cost. However, the application of LTE to MTC poses some unique challenges due to the large performance mismatch between the LTE user equipment and the MTC device, caused mainly by the physical limitations of most MTC devices. This article addresses these limitations, and examines their impact on the link performance and the corresponding link budget. The focus of this article is on the physical control channels. We address the issues of the existing LTE control channels, and propose an enhanced design specifically tailored for overcoming the limitations of MTC devices and meeting the stringent link budget requirement by applying repeated transmissions, spatial precoding, frequency hopping, and joint channel estimation. Finally, the design concept is extended to other channels such as the random access channel and the data channels.

Energy-Efficient Power and Time-Slot Allocation for Cellular-Enabled Machine Type Communications

Machine type communications (MTCs) over cellular networks pose significant challenges as a result of the large number of MTC devices (MTCDs), small and time controlled data transmissions, and rigorous energy limitation for small size MTCDs. This letter proposes an energy-efficient radio resource allocation (RRA) scheme for cellular-enabled MTCs, where user equipment (UEs) [used for human type communications (HTCs)] are configured as gateways for MTCs. On condition that the latency constraints for MTCs and HTCs are satisfied, our objectives are to minimize the total energy consumption of MTCDs and prolong network lifetime. Comparing with other RRA schemes, simulation results show that the proposed RRA scheme can achieve higher energy-efficiency and, therefore, extend network lifetime in LTE-A cellular networks.

Modelling RACH Arrivals and Collisions for Human Type Communication

This letter proposes an analytical model to evaluate the collision probability on the Random-Access CHannel (RACH) in Long-Term Evolution systems as a function of the number of user equipment, the number of available preambles, and the Inter–arrival times of the RACH Requests (IRRs) of the average user. The model for the IRR of the average user is obtained from real traffic data captured at the eNodeB of a mobile operator, and is derived by emulating the radio resource control (RRC) state machine for different RRCs Inactivity timer (RRC $_{\text {IT}}$ ) settings. The results of this letter suggest that when RRC $_{\text {IT}}$ is set to a few seconds, a mixture model is more accurate than the Poisson hypothesis both in modeling the IRR and in estimating the RACH performance.

Challenges of massive access in highly dense LTE-advanced networks with machine-to-machine communications

Machine-to-machine wireless systems are being standardized to provide ubiquitous connectivity between machines without the need for human intervention. A natural concern of cellular operators and service providers is the impact that these machine type communications will have on current human type communications. Given the exponential growth of machine type communication traffic, it is of utmost importance to ensure that current voice and data traffic is not jeopardized. This article investigates the limits of machine type communication traffic coexisting with human communication traffic in LTE-A networks, such that human customer churn is minimized. We show that under proper design, the outage probability of human communication is marginally impacted whilst duty cycle and access delay of machine type communications are reasonably bounded to ensure viable M2M operations.

Effect of a human-type communication robot on cognitive function in elderly women living alone

SummaryBackgroundConsidering the high prevalence of dementia, it would be of great value to develop effective tools to improve cognitive function. We examined the effects of a human-type communication robot on cognitive function in elderly women living alone.Material/MethodsIn this study, 34 healthy elderly female volunteers living alone were randomized to living with either a communication robot or a control robot at home for 8 weeks. The shape, voice, and motion features of the communication robot resemble those of a 3-year-old boy, while the control robot was not designed to talk or nod. Before living with the robot and 4 and 8 weeks after living with the robot, experiments were conducted to evaluate a variety of cognitive functions as well as saliva cortisol, sleep, and subjective fatigue, motivation, and healing.ResultsThe Mini-Mental State Examination score, judgement, and verbal memory function were improved after living with the communication robot; those functions were not altered with the control robot. In addition, the saliva cortisol level was decreased, nocturnal sleeping hours tended to increase, and difficulty in maintaining sleep tended to decrease with the communication robot, although alterations were not shown with the control. The proportions of the participants in whom effects on attenuation of fatigue, enhancement of motivation, and healing could be recognized were higher in the communication robot group relative to the control group.ConclusionsThis study demonstrates that living with a human-type communication robot may be effective for improving cognitive functions in elderly women living alone.

A Uniform Internet-Communicative Agent

A universal HTML-based communication is described and experimentally implemented in the EMA employment agent. EMA can contact any HTML-based program or database on the Internet on the basis of a single observation of a user filling input forms. After one observation, EMA is capable of gathering information on its own by modifying familiar input forms. While EMA in theory communicates with any other program on the Internet, its performance strongly relies on domain knowledge allowing reasonable guessing about the meaning of major input fields. Another human-type communication in the system is by speech using a Microsoft agent in English and our speech system in Slovenian. The system is in use for seven years. The number of accesses equals all residents in our country in one year.