B-com Institute of Research and Technology

The unavoidable transition from rigid dedicated hardware devices towards flexible containerized network services, introduced by Network Function Virtualization (NFV), brings novel opportunities while presenting several new challenges. Indeed, meeting the expectations of NFV in post-5G networks depends on the efficient placement of the services. The online placement of network services, demanding strict end-to-end latency requirements, with restricted computing resources presents a challenging problem which is worth investigating. We propose a Branch-and-Bound search approach for finding optimal placements of the network services by applying several cost functions to maximize the service acceptance. Extensive evaluations have been carried out, and the results confirm significant improvements when we consider a fair distribution of the resources on the edge.

Improvement of security is the subject of continuous efforts in telecommunication networks. As network architecture becomes more and more complex, so does the related security architecture. In 5G, the introduction of slicing induces increasing complexity as the network operator has to enforce a complex set of policies, including security policies, to share resources between the slices while ensuring their isolation. Simultaneously, slice owners may need to set up their own slice-level security policies, but this may cause conflicts with existing policies. In this paper, we propose a layered security architecture tailored to address security concerns both locally, e.g. at the slice level, and globally, e.g. at the inter-slice level. A key feature of this architecture is to allow slice owners to push their security policies into their slices. The architecture includes a policy conflict detector that detects policy conflicts between the network manager and its clients. Our solution further resolves those conflicts, and the policies are automatically applied to the network. This allows the network operator to safely authorize clients to set up custom security rules within their slices. To demonstrate the efficiency of our solution we implement the full architecture and evaluate the time necessary to propagate the client's rules.

In this work, we introduce a novel approach for depth estimation in a computer-generated hologram by employing horizontal segmentation of the reconstruction volume instead of conventional vertical segmentation. The reconstruction volume is divided into horizontal slices and each slice is processed using a residual U-net architecture to identify in-focus lines, enabling determination of the slice's intersection with the 3D scene. The individual slice results are then combined to generate a dense depth map of the scene. Our experiments demonstrate the effectiveness of our method, with improved accuracy, faster processing times, lower graphics processing unit (GPU) utilization, and smoother predicted depth maps than existing state-of-the-art models.

Digital reconstructions of numerical holograms enable data visualization and serve a multitude of purposes ranging from microscopy to holographic displays. Over the years, many pipelines have been developed for specific hologram types. Within the standardization effort of JPEG Pleno holography, an open-source MATLAB toolbox was developed that reflects the best current consensus. It can process Fresnel, angular spectrum, and Fourier-Fresnel holograms with one or more color channels; it also allows for diffraction-limited numerical reconstructions. The latter provides a way to reconstruct holograms at their intrinsic physical instead of an arbitrarily chosen numerical resolution. The Numerical Reconstruction Software for Holograms v10 supports all large public data sets featured by UBI, BCOM, ETRI, and ETRO, in their native and vertical off-axis binary forms. Through the release of this software, we hope to improve the reproducibility of research, thus enabling consistent comparison of data between research groups and the quality of specific numerical reconstructions.

Improving surgical training by means of technology assistance is an important challenge that aims to directly impact surgical quality. Surgical training includes the acquisition of two categories of knowledge: declarative knowledge (i.e. ‘knowing what’) and procedural knowledge (i.e. ‘knowing how’). It is essential to acquire both before performing any particular surgery. There are currently many tools for acquiring procedural knowledge, such as simulators. However, few approaches or tools allow a trainer to formalize and record surgical declarative knowledge, and a trainee to have easy access to it. In this paper, we propose an approach for structuring surgical declarative knowledge according to procedural knowledge and based on surgical process modeling. A dedicated software application has been implemented. We evaluated the concept and the software usability on two procedures with different medical populations: endoscopic third ventriculostomy involving 6 neurosurgeons and preparation of a surgical table for craniotomy involving 4 scrub nurses. The results of both studies show that surgical process models could be a well-adapted approach for structuring and visualizing surgical declarative knowledge. The software application was perceived by neurosurgeons and scrub nurses as an innovative tool for managing and presenting surgical knowledge. The preliminary results show that the feasibility of the proposed approach and the acceptability and usability of the corresponding software. Future experiments will study impact of such an approach on knowledge acquisition.

Augmented Reality (AR) applications have strong growth potential in clinical practices such as needle biopsy and surgery guidance and require important amounts of video data to be transferred with very low latency. In this context, devices and wires see their numbers grow in the Operating Room (OR) and a way to reduce this number is to use 5G transmission. The goal of this paper is to start demonstrating and measuring 5G capabilities inside the OR by setting up a real time AR application merging images from two medical modalities and over a 5G network. To provide a precise synchronization of the different incoming images, we will operate DICOM-RTV [1] (Real Time video) streams.

Integrated Access and Backhaul (IAB) allows to ease the deployment of gNodeBs (gNBs) in a 5G network by connecting them using cellular connectivity. The radio frequencies to achieve such a result can be the same as the ones used to connect User Equipment (UE) (in-band) or specific ones can be reserved (out-of-band). Both sub 6 GHz and millimeter wave (mmWave) frequencies can be used. IAB is relatively new and several contributions have been studying the lower layers (i.e. physical and link) in order to improve performance in scheduling and resource allocation. However, performance results are also very dependent on how the routing is implemented at the network layer which is an aspect that is not much studied in the state of the art. In this paper, we evaluate the performance of several IAB topologies against a topology without IAB-nodes. Results confirm the conclusions of the state of the art by showing that adding IAB-nodes significantly improve performance in terms of delay (more than 90 ms shorter delay) and Packet Delivery Ratio (PDR) (by up to 15 %), and also allows to extend the coverage area. These results reveal the high potential of IAB that could be improved even more using efficient routing.

This paper deals with multipath channel estimation and equalisation in low range (LoRa). It is suggested to take advantage of the cyclic property of the symbols in the LoRa frame preamble to obtain an interference-free version of the symbols in the frequency domain. Then, estimation methods used in multicarrier systems can be applied, such as the least square (LS), and the minimum mean square error (MMSE) estimators. It is shown that the cyclic property in LoRa is inherently independent of the length of the channel, making these estimation techniques robust to any frequency-selective channel. In addition the frequency domain zero-forcing (ZF) equaliser is used, and an original phase equaliser is introduced, taking advantage of the constant modulus property of LoRa symbols in the frequency domain. The performance of the investigated estimators and equalisers is shown through simulations, and applications to the presented results are further discussed.

With the current advancement in the medical world, surgeons are faced with the challenge of handling many sources of medical information in more and more complex and technological Operating Rooms (ORs). Obviously, in the next generation ones, there will be an increasing number of video flows during the surgery (e.g. endoscopes, cameras, ultrasounds, etc.), which can be also displayed all over the OR in order to facilitate the task for the surgeon and to avoid any adverse events or problems related to inadequate communication in the OR. Additionally, other information needs to be shared, pre/post/during an operation, such as the history of the digital images related to the patient in the PACS and the metadata coming from medical sensors. Moreover, these medical videos captured from the OR can be either displayed on a large screen in the OR in order to provide the surgeon with more visibility, in this case via DICOM-RTV, or streamed outside the OR via a P2P solution. The latter one can serve various purposes such as for teaching medical student in real-time or for remote- expertise with a remote senior surgeons. Hence, this paper addresses the challenges of streaming DICOM-RTV video and metadata flows live from the operating room, typically during an ongoing surgery, in real-time to the outside world. A Proof of Concept is also presented in order to demonstrate the feasibility of our solution.

Platform-as-a-Service (PaaS) cloud computing services have emerged in the last few years, offering an abstraction framework to enable the development, execution, and management of applications, which is de-coupled from complex infrastructure considerations. The next generation of PaaS solutions (NGPaaS) will have to address more stringent performance requirements compared to traditional PaaSes. They will have to support Telco-specific requirements in terms of resource efficiency, availability, and resilience. According to the 5G promise of convergence between vertical and Telco markets, they will also have to be able to address new use case scenarios. One of the possible scenarios to address could be the combining of Telco and vertical components as digital video broadcasting (DVB). This paper demonstrates how NGPaaS features enable the implementation of 5G-oriented connectivity services in cloud data centers. Regarding the convergence aspect, it aims to demonstrate how NGPaaS features facilitate the build of a combined Telco-broadcasting PaaS system on the cloud where a DVB-RCS2 system is able to bring its own components and integrate them with the connectivity services deployed on the PaaS by a Telco operator. This is achieved by applying specific customizations and enhancements to Kubernetes.