This note is devoted to multiperiodically operated complex system with inventory couplings transferring waste products from some subsystems as useful components to other subsystems. The flexibility of the inventory couplings is used to force each of the subsystems with its own period and to exploit its particular dynamic properties. This enhances the performance of the complex system endowed with many recycling loops, which reduce the amount of waste products endangering the natural environment. The subsystems are characterized by generalized populations composed of the individuals (the cycles), each of them encompasses its period, its initial state, its local control, and its inventory interaction. An evolutionary optimization algorithm employing such generalized populations coordinated on the basis of the inventory interaction constraints is developed. It includes the stability requirements imposed on the cyclic control processes connected with particular subsystems. The algorithm proposed is applied to the global multiperiodic optimization of some interconnected chemical production processes.
Abstract-In this paper, we analyse and compare two architectures providing an all-IP based connectivity and mobility for mobile devices over heterogeneous access technologies: Evolved Packet System (EPS) as specified by 3GPP and Secure Mobile Architecture (SMA), a standardization effort by The Open Group (TOG). We briefly present each architecture and qualitatively evaluate their advantages and disadvantages in terms of security, mobility, and support for location-based policy enforcement and security zoning. While SMA is capable of providing simultaneous multihoming, cryptographic identity-based packet tracking and ready support for location-based security zoning and policy control, EPS enables legal interception of user traffic and protection of user/host privacy by default.
This paper presents a performance evaluation of enhanced link adaptation techniques for MIMO-OFDM systems with imperfect feedback and channel estimation. In the link-level simulations, the channel modeling is based on MIMO channel measurements in line-of-sight and non line-of-sight scenarios. An adaptation process that switches between beamforming, diversity and multiplexing modes in combination with various modulation schemes is based on the effective SINR. Mutual information effective SINR mapping method is used as a part of the spatial and modulation scheme selection process due to its capability for estimating the error rate performance of large variety of MIMO channels accurately. Simulation results show that a simple adaptive system which applies diversity and multiplexing modes attains good performance in realistic 2 × 2 MIMO channels. It is also shown that the imperfect feedback and channel estimation can have a significant impact on the system performance.
In this paper, we present an advanced load balancing algorithm for Evolved Packet System utilizing different radio interfaces. By using the fact that Evolved Packet Core can support, in addition to LTE also multiple other packet data technologies, such as WLAN, we can utilize this additional dimension for benefit of load balancing for future mobile broadband networks. The main goal of the algorithm is to minimize the number of unsatisfied users in the network and thus load balancing algorithm is only active if those are present. We show a significant performance boost in network resource utilization and average data rate per user when employing the algorithm.
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