Multi-access Edge Computing (MEC) has become inevitable in future communication networks due to its pivotal role in latency critical and distributed services. New emerging services seek to further push the concept of MEC to user environments for localized, private and even quicker processing of information. Micro MEC (µMEC) fulfills such needs of emerging services. In this article, we provide an overview of the security landscape of the µMEC philosophy and technologies. Security challenges, potential solutions for those challenges are discussed and the missing gaps are highlighted to stir further research in this direction.

Wi-Fi technology has been thoroughly studied for indoor localization. This is mainly due to the existing infrastructure inside buildings for wireless connectivity and the uptake of mobile devices where Wi-Fi location-dependent measurements, e.g., timing and signal strength readings, are readily available to determine the user location. To enhance the accuracy of Wi-Fi solutions, a two-way ranging approach was recently introduced into the IEEE 802.11 standard for the provision of Fine Timing Measurements (FTM). Such measurements enable a more reliable estimation of the distance between FTM-capable Wi-Fi access points and user-carried devices; thus, promising to deliver meter-level location accuracy. In this work, we propose two novel solutions that leverage FTM and follow different approaches, which have not been investigated in the literature. The first solution is based on an Unscented Kalman Filter (UKF) algorithm to process FTM ranging measurements, while the second solution relies on an FTM fingerprinting method. Experimental results using real-life data collected in a typical office environment demonstrate the effectiveness of both solutions, while the FTM fingerprinting approach demonstrated 1.12m and 2.13m localization errors for the 67-th and 95-th percentiles, respectively. This is a two to three times improvement over the traditional Wi-Fi signal strength fingerprinting approach and the UKF ranging algorithm.

We propose a physical arrangement consisting of a 2.4 GHz WiFi radio, and high attenuation surfaces with an air-gap in-between, to delimit a fingerprinting region. We show by simulations, and field measurements, that such arrangement allows to form a characteristic lobe in the radiation pattern after the gap, which is characterized by an abrupt change in the Received Signal Strengths (RSSs) along the direction parallel to the surfaces. From measured RSS samples, we construct, to aid our analysis, an equation that approximates the radiation pattern as a continuous RSS radio map, using symbolic regression. Finally, we observe the positioning performance of this arrangement, performing RSS fingerprint pattern matching with a Neural Network. Results are compared to the positioning accuracy that would be obtained by using an omnidirectional radiation pattern antenna. We conclude that, the abrupt change in RSSs obtained with this arrangement, translates into a better positioning accuracy, close and along a direction parallel to the surfaces.

We consider a user-centric network-level coordination architecture for 5G heterogeneous Radio Access Networks (RANs), based on RAN softwarization and a centralized coordination framework. We describe the RAN as a set of logical RAN entities, related to cells in a Heterogeneous Network (HetNet), under the control of a central coordination entity. This description allows the creation of Network Functions (NFs) with an abstracted view of the network. We describe a centralized coordination framework, and then develop a NF for InterCell Interference Coordination (ICIC) in a 5G HetNet, optimizing the radio resource usage at network-level. We construct a Network Graph to abstract the problem of resource allocation and cell offloading, with the NF seeking for an optimal solution based on this abstraction. Simulations are performed in a HetNet scenario with a Tabu Search algorithm. Results show the feasibility of performing network-level coordination through a modular NF, with an abstracted view of the network.

In this paper, we provide a lower bound to maximum expected rate for block fading channels with limited Channel State Information (CSI). We assume a channel fading block accommodates at least one codeword so that for block Rayleigh fading, the ergodic channel capacity is zero when no CSI is available at the transmitter. The CSI fed back to the transmitter is subject to a cardinality constraint. We derive a counting function to describe an efficient use of the available cardinality by formulating the capacity loss due to limited cardinality as a variational calculus problem. The feedback schemes with different cardinality constraints can be easily derived by scaling the counting function to fit the cardinality constraints. With Rayleigh fading channels, the feedback scheme and the corresponding lower bound of maximum expected rate can be solved in closed form. According to our results, the expected rate achieved by using the counting function is tight.

This paper presents the design and implementation of a SIP proxy that enables inbound session initiation in the presence of network address translators. Furthermore, the implementation is used to evaluate a recently proposed IETF Internet-Draft. As a result, two problems were identified. This paper proposes a solution for these problems.