SDN-enabled Latency-Guaranteed Dual Connectivity in 5G RAN

A novel SDN-controlled E-UTRAN interacting with 5G Radio Resource Management (RRM) featuring Dual Connectivity (DC) is proposed and experimentally demonstrated. Radio bearers are dynamically steered to different evolved NodeBs, to guarantee effective per-flow latency performance.This work was partly funded by the project H2020-ICT-2014-1 “Wishful” (645274), and partly by EU H2020 5GTRANSFORMER project (761536)

Capacity and congestion aware flow control mechanism for efficient traffic aggregation in multi-radio dual connectivity

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Multi-Radio Dual Connectivity (MR-DC) is a key 3GPP technology that enables traffic aggregation between two base stations (BSs), and thus, increasing the per-user data rate. However, the schemes for traffic aggregation management of such technology are left up to vendor implementation. In this paper we show the importance of using an efficient traffic aggregation method to increase the throughput performance of both TCP and UDP-based applications in MR-DC operation. Targeting the gap on the state-of-the-art on this topic, we propose a cross-layer low control mechanism, which efficiently aggregates traffic based on the instantaneous available radio resources and buffering delay of both BSs. The aggregation is performed independently of the MR-DC architecture option, MAC scheduler logic, and transport layer protocol in use. By means of exhaustive testbed experiments, we show that the proposed method exceeds the performance of a benchmark and state-of-the-art low control solutions and achieves at least the 85% and 95% of the theoretical aggregate throughput for TCP and UDP traffic expected from the use of MR-DC, respectively.Peer ReviewedPostprint (published version

End-to-end performance evaluation of MEC deployments in 5G scenarios

Multi-access Edge Computing (MEC) promises to deliver localized computing power and storage. Coupled with low-latency 5G radio access, this enables the creation of high added-value services for mobile users, such as in-vehicle infotainment or remote driving. The performance of these services as well as their scalability will however depend on how MEC will be deployed in 5G systems. This paper evaluates different MEC deployment options, coherent with the respective 5G migration phases, using an accurate and comprehensive end-to-end (E2E) system simulation model (exploiting Simu5G for radio access, and Intel CoFluent for core network and MEC), taking into account user-related metrics such as response time or MEC latency. Our results show that 4G radio access is going to be a bottleneck, preventing MEC services from scaling up. On the other hand, the introduction of 5G will allow a considerable higher penetration of MEC services

User Association in 5G Networks: A Survey and an Outlook

26 pages; accepted to appear in IEEE Communications Surveys and Tutorial

Study of decoupled uplink and downlink access in 5G heterogeneus systems

El projecte analitzarà les funcionalitats i problemàtiques de l'Internet tàctil.Uplink and downlink decoupling (DUDe) is a disruptive technique that has been proposed recently to reduce the uplink and downlink imbalance problem, which occurs in HetNets due to the strong transmit power disparities between macro and small cells. In this thesis, previous research done on DUDe, in particular the association probability derivation, is used to calculate how the capacity is affected when the association is made to any SCell in the scenario. This specific situation is highly realistic since one or several small cells might be unavailable due to overload reasons. Therefore, one of the main objectives of this thesis is to evaluate and compare the potential capacity gains of decoupling to any other small cell in the scenario with respect to the macro cell, association that follows classical downlink received power policies. Decoupling uplink from the macro cell can improve as well the uplink outage, metric also evaluated and compared in this study. Moreover, there is a strong trend in research to empower multi-connectivity solutions, where one user has more than one uplink connection. We refer to this case as a dual connectivity scenario, and the uplink is further studied by allowing decoupled associations in dual connectivity scenarios. Dual connectivity in the uplink is highly controversial, since the user has limited power to share between two different access points. Therefore, a part from comparing the decoupled association performance with the downlink received power policies, this study compares the performance of multi-connectivity against having one single serving cell. In this case, a comparison is done with respect to the best uplink serving cell. Results show that decoupling the access increases the capacity even if there are some SCells unreachable and presents great performance on DC scenario.El uplink and downlink decoupling (DUDe) es una novedosa técnica propuesta recientemente para reduir el problema del uplink and downlink imbalance. El uplink and downlink imbalance ocurre cuando las potencias de las antenas de una heterogeneus network (HetNet) son muy dispares. En este proyecto, teniendo en cuenta la investigación realitzada hasta la fecha sobre el DUDe (especialmente sobre la probabilidad de asociación), se calcula la capacidad asociándose a cualquier SCell. Esta situación es muy importante ya que puede ser que algunes celdas sean inalcanzables por el usuario debido a que puedn estar sobrecargadas. Por este motivo, uno de los principales objetivos del proyecto es aavaluar la mejora de capacidad al relaizar el DUDe con cualquier SCell y mantenir la asociaciín con la MCell tal y como se ha hecho hasta ahora. Esta técnica se llama downlink receive power (DRP). El DUDe también mejora la outage probability, indicador que también se evalua en el estudio. En los estudios mas recientes también se trabaja con dual connectivity para mejorar las prestacions de la conexión. Aunque dividir la transmisión en el enlace de subida puede disminuir la capacidad debido a la baja potencia del usuario, se compara la capacidad de desacoplar el acceso en dual connectivity con el escenario de single best association. Los resultados muestran que el DUDe aumenta la capacidad aun teniendo algunes SCells inalcanzables. También se ha demostrado que el DUDe funciona perfectamente con la dual connectivity.L’Uplink and downlink decoupling és una innovadora tècnica que ha sigut proposada recentment per reduir el problema de l’uplink and downlink imbalance. L’uplink and downlink imbalance es dona a les heterogeneus networks (HetNets) degut a la disparitat de potències entre les diferents antenes. Durant aquest projecte, tenint en compte la recent recerca sobre DUDe (sobretot sobre la probabilitat d’associació), s’utilitza per calcular la capacitat a qualsevol SCell. Aquesta situació és molt important d’analitzar ja que pot ser possible que algunes no estiguin accessibles per sobrecàrrega. Per aquest motiu, un dels principals objectius del projecte és avaluar la millora de capacitat entre realitzar el DUDe a qualsevol SCell i mantenir l’associació amb la MCell com s’havia fet fins ara, el que es coneix com downlink receive power (DRP). El DUDe també comporta moltes millores a la outage probability, indicador que també s’avalua a l’estudi. En els estudis més recents també treballen amb dual connectivity per millorar les prestacions. Tot i que dividir la transmissió a l’enllaç de pujada pot comportar perdre capacitat degut a la baixa potència de l’usuari, es compara la capacitat amb el DUDe en un escenari de dual connectivity amb el cas de single best association. Els resultats mostren que el fet de desacoblar l’accés augmenta la capacitat de la connexió tot i tenir algunes SCells inabastables. També s’ha demostrat que el DUDe funciona perfectament amb la dual connectivity

Multi-connectivity in 5G New Radio: configuration algorithms and performance evaluation

The 5th Generation (5G) New Radio (NR) air interface is expected to be the foundation of very heterogeneous networks serving a wide range of use cases, including Ultra-Reliable Low Latency Communications (URLLC) services. In URLLC, small data packets must be correctly transmitted and received in a short time with high reliability (up to 1 ms latency with a success probability of 99.999%). Different options are being considered to meet this challenging design target. One such considered solution is data duplication through dual connectivity, where the same packet is independently transmitted through two different nodes. This project studies the functionality of data duplication at PDCP level for dual connectivity through system-level simulations, where each packet copy is sent through the two links to which a certain UE is connected. The studied scenario is a heterogeneous network of 21 macro cells with a cluster of 4 pico cells per macro cell area. The scenario is first optimized for the single connectivity case, which supports up to 8Mbps URLLC load while meeting the URLLC requirements. When dual connectivity is enabled, in a controlled manner, in a URLLC traffic only scenario, it is shown that dual connectivity does not provide any gain due to the low interference conditions. As second step, the benefit of DC is studied when the URLLC traffic coexist with full buffer background eMBB traffic. Results show that latency gain can be obtained by dual connectivity, however the sensitivity of this gain on the scenario conditions is quite high. Finally, an optimization is added, in which if a packet sent through one of the links is successfully received at the UE, the transmission of its copy on the other link is cancelled (i.e. the packet is discarded at the network side). This optimization results in a performance improvement in terms of the latency especially at high load because it avoids buffering delay

On Dependable Wireless Communications through Multi-Connectivity

The realization of wireless ultra-reliable low-latency communications (URLLC) is one of the key challenges of the fifth generation (5G) of mobile communications systems and beyond. Ensuring ultra-high reliability together with a latency in the (sub-)millisecond range is expected to enable self-driving cars, wireless factory automation, and the Tactile Internet. In wireless communications, reliability is usually only considered as percentage of successful packet delivery, aiming for 1 − 10⁻⁵ up to 1 − 10⁻⁹ in URLLC