On Supporting Small M2M Data Transmissions in LTE/LTE-A Networks

In Machine-to-Machine (M2M) applications, devices monitor events (e.g., temperature, inventory level), which is relayed through a communication network infrastructure (e.g. Internet, LTE) to an application (software program running on a server connected to the Internet), that translates the monitored event into some meaningful information to be able to take collaborative decisions with limited or no human intervention. With the availability of IPv6 address, it is possible to interconnect everything in this universe. By using the concept of interconnecting things, several applications can be envisioned to make the world smarter. Internet of Things (IoT) is a paradigm whose aim is to implement the concept of interconnection of everything by using all possible technologies and others means. M2M communica- tion is one of the components of Internet of Things (IoT) whose goal is to make the communication smooth and seamless between any two networking enabled devices. According to the researchers by the end of 2014, 1.5 billion devices and by the end of 2020, 20 billion devices will be part of M2M communication

Adaptive RACH Congestion Management to Support M2M Communication in 4G LTE Networks

Machine to machine communication (M2M) or machine type communication (MTC) facilitates communication of two network enabled devices, without any human intervention, to take some intelligent decision based on the interaction of devices. Because of ubiquitous coverage and global connectivity, cellular networks are playing a major role in the deployment of M2M communications. Due to some unique characteristics of M2M communication, supporting M2M applications in cellular networks is very challenging. One of such challenge is congestion in radio access network (RAN) during RACH procedure. This is because of the fact that there are large numbers of M2M devices which access the radio network at the same time. As a solution, we propose an adaptive RACH congestion management function (ARC) which specifies congestion handling method to be used by all M2M devices based on the current congestion condition of the networ

Magnetic Structures of High Temperature Phases of TbBaCo2O5.5

Neutron diffraction studies have been carried out on a single crystal of oxygen-deficient perovskite TbBaCo2O5.5 in the temperature range of 7-370 K. There have been observed several magnetic or structural transitions. Among these, the existence of the transitions to the insulating phase from the metallic one at ~340 K, to the one with the ferromagnetic moment at ~280 K and possibly to the antiferromagnetic one at ~260 K, with decreasing temperature T correspond to those reported in former works. We have studied the magnetic structures at 270 K and 250 K and found that all Co3+ ions of the CoO6 octahedra are in the low spin state and those of the CoO5 pyramids carry spins which are possibly in the intermediate spin state. Non-collinear magnetic structures are proposed at these temperatures. Two other transitions have also been observed at the temperatures, ~100 K and ~250 K.Comment: 9 pages, 2 tables, 10 figure

Clock Gating Based Energy Efficient ALU Design and Implementation on FPGA

In this paper, latch free clock gating techniques is applied in ALU to reduce clock power and dynamic power consumption of ALU. Clock power is 50%, 41.46%, 51.30%, 55.15% and 55.78% of total dynamic power when device operating frequency is 100MHz, 1GHz, 10GHz, 100GHz and 1 THz. After implementation of clock gating techniques in ALU, Clock power reduces to 17.85%, 23.39%, 26.49% and 27.19% of total dynamic power, when device operating frequency is 1GHz, 10GHz, 100GHz and 1 THz. On 1 THz operating frequency, when we use clock gating, there are 72.77% reduction in clock power, 38.88% reduction in IOs power and 44% reduction in dynamic power in compare to power consumption without using clock gating techniques. Target device is 90-nm Spartan-3. There is 14.57% reduction in junction temperature on 10GHz operating frequency in compare to temperature without using clock gating techniques. Clock gating saves power but increases over all area. There is 32.35%, 37.84%, 43.31% and 44% reduction in dynamic current when we use clock gate on 1GHz, 10GHz, 100GHz and 1THz operating frequency respectivel

Class based priority scheduling to support Machine to Machine communications in LTE systems

Due to the ubiquitous coverage and seamless connectivity, cellular systems are very promising to support Machine-to-Machine (M2M) communications. But, all of the cellular networks are designed and optimized for Human-to-Human (H2H) or Human-to-Machine (H2M) communications and therefore facing several challenges due to incorporation of M2M communications. One of such challenges is efficient resource allocation to M2M applications without affecting or least affecting H2H applications. In order to address this challenge, we need application specific priority based scheduling algorithms in which based on the QoS of the application, radio resources are allocated. In this paper, we have classified and prioritized all H2H and M2M flows based on their QoS requirements. Resources are allocated first to higher priority classes and in a given class, they are allocated to H2H flows first. In order to ensure the QoS of H2H flows, a threshold is kept on the maximum number of radio resource blocks to be assigned to M2M flows in a scheduling interval. Performance of the proposed scheduling algorithm is evaluated using various metrics such as system throughput and average utility per class and compared against existing scheduling scheme

Class based dynamic priority scheduling for uplink to support M2M communications in LTE

Machine-to-Machine (M2M) communication has emerged as a key technology with huge market potential for cellular service providers deploying LTE networks. Addition of enormous number of M2M devices into the cellular networks poses a heavy competition to existing Human-to-Human (H2H) devices for getting radio resources, thereby affecting the performance of the H2H communications. But, one can not treat all M2M flows as low priority and schedule them after H2H flows, as there are many M2M applications like healthcare and tracking which are of high importance and delay-intolerant. Hence, there is a need for class based priority scheduling of the traffic of M2M and H2H sessions in the network. In this paper, we propose a class based dynamic priority scheduling algorithm for uplink transmission of M2M and H2H traffic in LTE. The performance of the algorithm is evaluated by various metrics such as H2H throughput and system throughput and also compared with existing scheduler

Spin state equilibria and localized versus collective d-electron behaviour in neodymium and gadolinium trioxocobaltate(III)

Magnetic susceptibility measurements and mossbauer spectra show that NdCoO<SUB>3</SUB> and GdCoO<SUB>3</SUB> contain predominantly low-spin Co<SUP>III</SUP> ions at low temperatures which transform partially to high-spin Co<SUP>3+</SUP> until a certain temperature. Beyond this temperature, there is a transfer of e<SUB>g</SUB> electrons from Co<SUP>3+</SUP> to Co<SUP>III</SUP> giving rise to di- and tetra-valent Co species followed by short-range ordering. Co<SUP>3+</SUP> ions completely disappear at about 1000 K where there is a gradual transition from localized electron behaviour to collective behaviour. The cobaltates are semi-metals beyond this transition. The spin state equilibria and the electronic transition described here find support from electron transport properties, mossbauer parameters as well as differential thermal analysis and x-ray data

Mossbauer studies of the high-spin-low-spin equilibria and the localized-collective electron transition in LaCoO<SUB>3</SUB>

Mossbauer studies combined with magnetic-susceptibility data on well-characterized LaCoO<SUB>3</SUB> in the 4.2-1200-K region show that cobalt ions exist predominantly in the low-spin Co<SUP>III</SUP> state at low temperatures which transform partially to high-spin Co<SUP>3+</SUP> ions up to 200 K. Above 200 K, Co<SUP>3+</SUP> and Co<SUP>III</SUP> ion pairs transform to Co<SUP>II</SUP> and Co<SUP>4+</SUP> pairs. At high temperatures, the population of Co<SUP>3+</SUP> decreases significantly and completely disappears at the localized-electron-collective-electron transition temperature at 1210 K. The variations of the lamb-mossbauer factor and the center shift with temperature provide valuable information on the high-spin-low-spin equilibria, as well as on the nature of the phase transitions and symmetry changes in LaCoO<SUB>3</SUB>. All these changes are reflected in the transport properties of LaCoO<SUB>3</SUB>. There appears to be little doubt that the first-order localized-electron-collective-electron transition in LaCoO<SUB>3</SUB> is caused essentially by the change in entropy of the d electrons

Itinerant-electron ferromagnetism in La<SUB>1-x</SUB>Sr<SUB>x</SUB>CoO<SUB>3</SUB>: a Mossbauer study

Mossbauer and other studies establish that in La<SUB>1-x</SUB>Sr<SUB>x</SUB>CoO<SUB>3</SUB> (x&gt;0.125), ferromagnetic Sr<SUP>2+</SUP>-rich clusters coexist with paramagnetic La<SUP>3+</SUP>-rich regions in the same crystallographic phase, with the ferromagnetic component increasing with increasing x and decreasing T. The 3d holes created by Sr<SUP>2+</SUP> substitution are itinerant both above and below T<SUB>C</SUB>. All the experimental observations on this system can be explained on the basis of itinerant-electron ferromagnetism

Spin-state equilibria in holmium cobaltate

Mossbauer and magnetic susceptibility studies of HoCoO<SUB>3 </SUB>have shown that there is coexistence of low-spin Co(III) ions and high-spin Co<SUP>3+</SUP> ions; Co(III) being more predominant at low temperatures. The population of Co(III) and Co<SUP>3+</SUP> equalizes above a particular temperature with these ions occupying alternate oxygen octahedra, leading to an ordered phase. The ordering transition is evidenced by the temperature variation of Lamb-Mossbauer factor, x-ray Debye-Waller factor, and inverse susceptibility. Electrical-conductivity data reflect these changes in the spin-state equilibria and show that at around 1080 K, HoCoO3 becomes metallic. At this temperature, a first-order localized electron-collective electron transition seems to occur. Co(II) and Co<SUP>4+</SUP> are not formed by electron transfer from Co<SUP>3+</SUP> to Co(III) as in LaCoO<SUB>3</SUB>. This behavior is correlated with the variation of covalency in the cobaltates