35 research outputs found
Storms in mobile networks
Mobile networks are vulnerable to signalling attacks and storms caused by traffic that overloads the control plane through excessive signalling, which can be introduced via malware and mobile botnets. With the advent of machine-to-machine (M2M) communications over mobile networks, the potential for signalling storms increases due to the normally periodic nature of M2M traffic and the sheer number of communicating nodes. Several mobile network operators have also experienced signalling storms due to poorly designed applications that result in service outage. The radio resource control (RRC) protocol is particularly susceptible to such attacks, motivating this work within the EU FP7 NEMESYS project which presents simulations that clarify the temporal dynamics of user behavior and signalling, allowing us to suggest how such attacks can be detected and mitigated
Performance analysis of mobile networks under signalling storms
There are numerous security challenges in cellular mobile networks, many of which originate from the Internet world. One of these challenges is to answer the problem with increasing rate of signalling messages produced by smart devices. In particular, many services in the Internet are provided through mobile applications in an unobstructed manner, such that users get an always connected feeling. These services, which usually come from instant messaging, advertising and social networking areas, impose significant signalling loads on mobile networks by frequent exchange of control data in the background. Such services and applications could be built intentionally or unintentionally, and result in denial of service attacks known as signalling attacks or storms. Negative consequences, among others, include degradations of mobile network’s services, partial or complete net- work failures, increased battery consumption for infected mobile terminals.
This thesis examines the influence of signalling storms on different mobile technologies, and proposes defensive mechanisms. More specifically, using stochastic modelling techniques, this thesis first presents a model of the vulnerability in a single 3G UMTS mobile terminal, and studies the influence of the system’s internal parameters on stability under a signalling storm. Further on, it presents a queueing network model of the radio access part of 3G UMTS and examines the effect of the radio resource control (RRC) inactivity timers. In presence of an attack, the proposed dynamic setting of the timers manage to lower the signalling load in the network and to increase the threshold above which a network failure could happen. Further on, the network model is upgraded into a more generic and detailed model, represent different generations of mobile technologies. It is than used to compare technologies with dedicated and shared organisation of resource allocation, referred to as traditional and contemporary networks, using performance metrics such as: signalling and communication delay, blocking probability, signalling load on the network’s nodes, bandwidth holding time, etc. Finally, based on the carried analysis, two mechanisms are proposed for detection of storms in real time, based on counting of same-type bandwidth allocations, and usage of allocated bandwidth. The mechanisms are evaluated using discrete event simulation in 3G UMTS, and experiments are done combining the detectors with a simple attack mitigation approach.Open Acces
Towards 5G Zero Trusted Air Interface Architecture
5G is destined to be supporting large deployment of Industrial IoT (IIoT)
with the characteristics of ultra-high densification and low latency. 5G
utilizes a more intelligent architecture, with Radio Access Networks (RANs) no
longer constrained by base station proximity or proprietary infrastructure. The
3rd Generation Partnership Project (3GPP) covers telecommunication technologies
including RAN, core transport networks and service capabilities. Open RAN
Alliance (O-RAN) aims to define implementation and deployment architectures,
focusing on open-source interfaces and functional units to further reduce the
cost and complexity. O-RAN based 5G networks could use components from
different hardware and software vendors, promoting vendor diversity,
interchangeability and 5G supply chain resiliency. Both 3GPP and O-RAN 5G have
to manage the security and privacy challenges that arose from the deployment.
Many existing research studies have addressed the threats and vulnerabilities
within each system. 5G also has the overwhelming challenges in compliance with
privacy regulations and requirements which mandate the user identifiable
information need to be protected.
In this paper, we look into the 3GPP and O-RAN 5G security and privacy
designs and the identified threats and vulnerabilities. We also discuss how to
extend the Zero Trust Model to provide advanced protection over 5G air
interfaces and network components
Measurements and Analysis of YouTube Traffic Profile and Energy Usage with LTE DRX Mode
In this thesis, YouTube data profile is examined in order to find transmitting patterns which could be used for increasing transmission efficiency during video transmission. The emphasis is on Discontinuous Reception (DRX) and a promotion timer, which is in control when a mobile station moves from the RRC_CONNECTED state to the RRC_IDLE state in Long Term Evolution (LTE) networks.
After the measurements and a result analysis, a new Matlab model for YouTube data transmission is presented. Additionally, another model for YouTube energy calculations in LTE network is derived.
The studies indicate that 97 % of YouTube traffic is transmitted in two parallel Transmission Control Protocol (TCP) streams. There is a 10-second speedup phase where 20 % of the video is transmitted at the beginning of the transfer that is followed by a steady phase where idle and transmission periods alternate. All of the video data has been delivered when 74 % of the viewing has elapsed. There are also dozens of small TCP streams that break idle periods into a few seconds. Delaying transmission of these small TCP streams allows longer idle periods and can result in up to 30 % energy savings with small promotion timer values
Towards efficient support for massive Internet of Things over cellular networks
The usage of Internet of Things (IoT) devices over cellular networks is seeing tremendous
growth in recent years, and that growth in only expected to increase in the near
future. While existing 4G and 5G cellular networks offer several desirable features for
this type of applications, their design has historically focused on accommodating traditional
mobile devices (e.g. smartphones). As IoT devices have very different characteristics
and use cases, they create a range of problems to current networks which often
struggle to accommodate them at scale. Although newer cellular network technologies,
such as Narrowband-IoT (NB-IoT), were designed to focus on the IoT characteristics,
they were extensively based on 4G and 5G networks to preserve interoperability, and
decrease their deployment cost. As such, several inefficiencies of 4G/5G were also
carried over to the newer technologies.
This thesis focuses on identifying the core issues that hinder the large scale deployment
of IoT over cellular networks, and proposes novel protocols to largely alleviate
them. We find that the most significant challenges arise mainly in three distinct areas:
connection establishment, network resource utilisation and device energy efficiency.
Specifically, we make the following contributions. First, we focus on the connection
establishment process and argue that the current procedures, when used by IoT devices,
result in increased numbers of collisions, network outages and a signalling overhead
that is disproportionate to the size of the data transmitted, and the connection duration
of IoT devices. Therefore, we propose two mechanisms to alleviate these inefficiencies.
Our first mechanism, named ASPIS, focuses on both the number of collisions
and the signalling overhead simultaneously, and provides enhancements to increase the
number of successful IoT connections, without disrupting existing background traffic.
Our second mechanism focuses specifically on the collisions at the connection establishment
process, and used a novel approach with Reinforcement Learning, to decrease
their number and allow a larger number of IoT devices to access the network with fewer
attempts.
Second, we propose a new multicasting mechanism to reduce network resource
utilisation in NB-IoT networks, by delivering common content (e.g. firmware updates)
to multiple similar devices simultaneously. Notably, our mechanism is both more efficient
during multicast data transmission, but also frees up resources that would otherwise
be perpetually reserved for multicast signalling under the existing scheme.
Finally, we focus on energy efficiency and propose novel protocols that are designed
for the unique usage characteristics of NB-IoT devices, in order to reduce the
device power consumption. Towards this end, we perform a detailed energy consumption
analysis, which we use as a basis to develop an energy consumption model for
realistic energy consumption assessment. We then take the insights from our analysis,
and propose optimisations to significantly reduce the energy consumption of IoT
devices, and assess their performance
Security in Computer and Information Sciences
This open access book constitutes the thoroughly refereed proceedings of the Second International Symposium on Computer and Information Sciences, EuroCybersec 2021, held in Nice, France, in October 2021. The 9 papers presented together with 1 invited paper were carefully reviewed and selected from 21 submissions. The papers focus on topics of security of distributed interconnected systems, software systems, Internet of Things, health informatics systems, energy systems, digital cities, digital economy, mobile networks, and the underlying physical and network infrastructures. This is an open access book