Changes In Mobility Networks Research Articles

NETWORK SECURITY ISSUES AND SECURITY ATTACK CLASSIFICATION FOR 5G

Fifth-generation technology [5G] services commercialized in 2019 have not only provided voice and data communication but also undergone significant structural changes in mobile networks to accommodate Internet-of-things devices, sensitive to latency and reliability, by adopting the latest ICT technologies, such as software-defined networking/network function virtualization, multi-access edge computing, and network slicing. However, this technological evolution poses new security chal- lenges, such as creation of new access paths, owing to its complex inter-operation structures, security downgrading, and limitations in security visibility. To address these issues, research on 5G security threats and security architecture has been actively underway at international standards organizations, communication carriers, and universities. However, security researchers find it difficult to conduct studies on 5G security technology design and application methods owing to the relatively unknown nature of the mobile carrier network. Therefore, in this paper, we analyzed five new security issues for each 5G section, relative to 5G technical advantages, by reviewing previous studies. In addition, we classified cyber attacks against nine network protocols primarily used in the 5G core network. The result of this study is expected to be used as basic data for modeling 5G security threats. Keywords: 5G security, Internet of things, 5G security technology, Cyber attacks, 5G threats

COVID-19 lockdown induces disease-mitigating structural changes in mobility networks

In the wake of the COVID-19 pandemic many countries implemented containment measures to reduce disease transmission. Studies using digital data sources show that the mobility of individuals was effectively reduced in multiple countries. However, it remains unclear whether these reductions caused deeper structural changes in mobility networks and how such changes may affect dynamic processes on the network. Here we use movement data of mobile phone users to show that mobility in Germany has not only been reduced considerably: Lockdown measures caused substantial and long-lasting structural changes in the mobility network. We find that long-distance travel was reduced disproportionately strongly. The trimming of long-range network connectivity leads to a more local, clustered network and a moderation of the "small-world" effect. We demonstrate that these structural changes have a considerable effect on epidemic spreading processes by "flattening" the epidemic curve and delaying the spread to geographically distant regions.

Performance Improvement of Topology-Transparent Broadcast Scheduling in Mobile Ad Hoc Networks

Broadcasting is a key function in mobile ad hoc networks. Topology-dependent scheduling algorithms depend on the detailed network connectivity information and cannot adapt to dynamic topological changes in mobile networks. To overcome this limitation, topology-transparent broadcast scheduling algorithms have been proposed. Due to the large overhead of implement- ing the acknowledgement mechanism in broadcast communica- tions and to guarantee that there is at least one collision-free transmission in each frame, most existing topology-transparent broadcast scheduling algorithms require a node to transmit the same packet repeatedly at multiple slots during one frame. This is very inefficient. In this paper, we propose an efficient topology- transparent broadcast scheduling algorithm. First, instead of transmitting the same packet repeatedly during one frame, each node collects transmission codes of its two-hop neighbors and transmits several different packets during one frame. Second, noting that many unassigned slots are not utilized, we propose several methods to utilize the unassigned slots efficiently in a collision-free and traffic-adaptive manner. Thus, our algorithm provides a guaranteed throughput and achieves a much better average throughput. The analytical and simulation results show that our proposed algorithm outperforms other existing topology- transparent broadcast algorithms dramatically.