Provisioning multimedia wireless networks for better QoS: RRM strategies for 3G W-CDMA

Third-generation mobile communication systems will bring a wide range of new services with different quality of service requirements and will open the ability to exploit radio resource management functions to guarantee a certain target QoS, to maintain the planned coverage area and to offer a high-capacity while using the radio resources in an efficient way. RRM functions impact the overall system efficiency and the operator infrastructure cost, so they will definitively play an important role in a mature 3G scenario. In order to provide some insight into radio resource management (RRM) strategies implementation, a range of representative case-studies with several innovative algorithms are presented and supported by simulation results in a realistic UMTS Terrestrial Radio Access Network scenario as devised in the 3GGP standardization forum. In particular, a decentralized uplink transmission rate selection algorithm in the short term, a congestion control mechanism to cope with overload situations, and downlink scheduling for layered streaming video packets are proposed.     

An emulator framework for a new radio resource management for QoSguaranteed services in W-CDMA systems

In the context of third-generation (3G) systems a mix of services with different requirements are expected. Consequently, packet scheduling mechanisms for quality of service (QoS) guarantees will play a key role. This paper proposes a new scheduling strategy that makes consistent the target quality in the radio link with the priority level assigned to each user. The performance of such a strategy is assessed by system level simulations and, in order to gain more insight into the difficulties of this optimization problem, it is compared to other alternatives. This work is part of the Wineglass project, within the Fifth Framework Program of the European Commission (IST), where a real time demonstrator including the radio resource management tasks is being developed. Thus, an implementation approach of the proposed scheduling is also described. The implementation is based on lookup tables and this approach is validated by simulation     

Average block error probability in the reverse link of a packetDS/CDMA system under Rayleigh fading channel conditions

Analytic expressions have been derived for the probability density functions of the total signal-to-interference ratio when considering mixed-type interference sources in the reverse link of a DS/CDMA packet radio system with Rayleigh fading. Four different scenarios were studied, and the corresponding expressions are presented for each situation. The users are divided into two groups: those that apply a closed-loop power control and those that only use an open-loop power control. By making use of these expressions, the mean block error probability is derived as a function of the number of total interfering users in each group     

On the Optimum Traffic Allocation in Heterogeneous CDMA/TDMA Networks

This paper presents the optimum user allocation in heterogeneous scenarios with CDMA and TDMA technologies in order to minimize the total outage probability in the uplink. An analytical model reflecting the different nature of the two access technologies is presented in order to formulate the optimization procedure. It is shown how the optimum allocation depends on the specific parameters of the two technologies, as illustrated with some representative results. The proposed optimization methodology is claimed to have applicability in the field of common radio resource management strategies for beyond 3G networks.     

Introducing Mobile Edge Computing Capabilities through Distributed 5G Cloud Enabled Small Cells

Current trends in broadband mobile networks are addressed towards the placement of different capabilities at the edge of the mobile network in a centralised way. On one hand, the split of the eNB between baseband processing units and remote radio headers makes it possible to process some of the protocols in centralised premises, likely with virtualised resources. On the other hand, mobile edge computing makes use of processing and storage capabilities close to the air interface in order to deploy optimised services with minimum delay. The confluence of both trends is a hot topic in the definition of future 5G networks. The full centralisation of both technologies in cloud data centres imposes stringent requirements to the fronthaul connections in terms of throughput and latency. Therefore, all those cells with limited network access would not be able to offer these types of services. This paper proposes a solution for these cases, based on the placement of processing and storage capabilities close to the remote units, which is especially well suited for the deployment of clusters of small cells. The proposed cloud-enabled small cells include a highly efficient microserver with a limited set of virtualised resources offered to the cluster of small cells. As a result, a light data centre is created and commonly used for deploying centralised eNB and mobile edge computing functionalities. The paper covers the proposed architecture, with special focus on the integration of both aspects, and possible scenarios of application.     

Biogenic amines and HL60 citotoxicity of alfalfa and fenugreek sprouts

The use of germinated seeds as food originated in far east countries and has recently spread to the western world where they are seen as fresh and healthy ingredients. While sprouted alfalfa is widely consumed, sprouted fenugreek seeds are not commonly produced, yet could be active ingredients for blood glucose and cholesterol control. As part of a safety evaluation of sprouted alfalfa and fenugreek flours, as novel ingredients for use in functional foods, their contents of biogenic amines and HL60 cytotoxicity were studied. Alfalfa (Medicago sativa) and fenugreek (Trigonella foenum-graecum) were germinated or 4 days at 20 °C and 30 °C, with and without light. Ungerminated seeds contained putrescine, cadaverine, histamine, tyramine, spermidine and spermine. Bioactive amine levels found in alfalfa sprouts were twice higher than those found in raw seeds and germination at 20 °C without light provided the lowest levels of total biogenic amines. In sprouted fenugreek, only putrescine and cadaverine increased during germination and temperature and light exposure brought about little change. The amount of biogenic amines in sprout seeds was always below acceptable healthy levels. Results obtained in HL60 leukemic cells showed apoptosis, cell proliferation and cell viability values similar to those found for distilled water and no toxic effects were found. The results provide support for the use of germinated alfalfa and fenugreek seeds as ingredients in functional foods.     

Cross-layer scheduling strategy for UMTS downlink enhancement

This article describes the benefits of including cross-layer information in the scheduling mechanism of a UMTS downlink channel. In particular, the information obtained from the fast power control algorithm is used to properly schedule transmissions. A prioritization function that exploits the short-term channel variations is proposed. This strategy is shown to be a feasible approach to improve system performance in terms of capacity and delay. This enhancement is obtained as a benefit of intrinsic multi-user diversity. The proposal is applicable within the current UMTS radio resource management framework.     

Periodic growth in rats

Microknemometry, a novel non-invasive technique, allows the accurate measurements of the lower leg length in the conscious rat, not only daily but even in periods smaller than 24 hours. Its use revealed the presence of nonlinear growth increments (mini-growth spurts) with periods between 4 and 5 days, that presented a gradual decline in amplitude when the animals were getting older, and a maximal growth rate between 0600h and 0900h. A sexual dimorphic growth pattern could be established with females growing less and presenting spurts of lower amplitude and smaller duration than males. High doses of recombinant human Growth Hormone (rhGH) stimulated growth velocity in female rates, but did not show any effect on males. Neonatal Monosodium Glutamate (MSG) treatment reduced growth both in males and females. Growth hormone (GH) replacement therapy in MSG treated animals was capable of increasing growth velocity, from day 30 onwards. The recovery was partial in males and complete in females. In intact male rats growth blockade induced by fasting was not followed by a catch up effect after refeeding, although growth velocity tended to increase and a clear catch up effect on weight was detected. Male rats seemed to grow at a maximal speed over at least the first 60 days of life, that cannot be accelerated with GH treatment, whereas female rats did respond to exogenous GH.     

On WCDMA base station selection criteria

This letter presents a BS selection criterion for WCDMA that allows selecting the base station requiring the minimum transmission power in both the uplink and downlink direction. The importance of minimizing transmitted power lies on the associated interference reduction and, consequently, the capacity increase. Furthermore, it is shown that, with a proper setting of the parameters, the criterion used in practical WCDMA systems based on Ec/Io measurements can be adjusted to provide results similar to the proposed method.     

An adaptive ISMA-DS/CDMA MAC protocol for third-generation mobilecommunications systems

An inhibit sense multiple access-direct sequence/code division multiple access (ISMA-DS/CDMA) medium access control protocol for a packet transmission mobile radio network is presented. The main feature of this protocol is its ability to retain the inherent flexibility of random access protocols while at the same time reducing to some extent the randomness in the access in order to increase the system capacity. In this framework, the protocol is presented together with some adaptive mechanisms that improve the protocol performance by means of regulating the access and varying the transmission bit rate according to the channel load that is broadcast by the base station. As a result, an adaptive bit rate algorithm is presented that reaches a throughput value close to the theoretical maximum