Call admission control algorithms in OFDM-based wireless multiservice networks

Orthogonal frequency division multiplexing(OFDM) is becoming a fundamental technology in future generation wireless communications. Call admission control is an effective mechanism to guarantee resilient, efficient, and quality-of-service (QoS) services in wireless mobile networks. In this paper, we present several call admission control algorithms for OFDM-based wireless multiservice networks. Call connection requests are differentiated into narrow-band calls and wide-band calls. For either class of calls, the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its QoS requirement. The batch size is a random variable following a probability mass function (PMF) with realistically maximum value. In addition, the service times for wide-band and narrow-band calls are different. Following this, we perform a tele-traffic queueing analysis for OFDM-based wireless multiservice networks. The formulae for the significant performance metrics call blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms is discussed. Moreover, the analytical model has been validated by simulation. The methodology as well as the result provides an efficient tool for planning next-generation OFDM-based broadband wireless access systems.

Interprofessional attitudes amongst undergraduate students in the health professions: a longitudinal questionnaire survey

Background: Interprofessional education (IPE) introduced at the beginning of pre-registration training for healthcare professionals attempts to prevent the formation of negative interprofessional attitudes which may hamper future interprofessional collaboration. However, the potential for IPE depends, to some extent, on the readiness of healthcare students to learn together. Objectives: To measure changes in readiness for interprofessional learning, professional identification, and amount of contact between students of different professional groups; and to examine the influence of professional group, student characteristics and an IPE course on these scores over time. Design: Annual longitudinal panel questionnaire survey at four time-points of pre-registration students (n = 1683) drawn from eight healthcare groups from three higher education institutions (HEIs) in the UK. Results: The strength of professional identity in all professional groups was high on entry to university but it declined significantly over time for some disciplines. Similarly students’ readiness for interprofessional learning was high at entry but declined significantly over time for all groups, with the exception of nursing students. A small but significant positive relationship between professional identity and readiness for interprofessional learning was maintained over time. There was very minimal contact between students from different disciplines during their professional education programme. Students who reported gaining the least from an IPE course suffered the most dramatic drop in their readiness for interprofessional learning in the following and subsequent years; however, these students also had the lowest expectations of an IPE course on entry to their programme of study. Conclusion: The findings provide support for introducing IPE at the start of the healthcare students’ professional education to capitalise on students’ readiness for interprofessional learning and professional identities, which appear to be well formed from the start. However, this study suggests that students who enter with negative attitudes towards interprofessional learning may gain the least from IPE courses and that an unrewarding experience of such courses may further reinforce their negative attitudes.