Elastic Multi-resource Network Slicing: Can Protection Lead to Improved Performance?

In order to meet the performance/privacy requirements of future data-intensive mobile applications, e.g., self-driving cars, mobile data analytics, and AR/VR, service providers are expected to draw on shared storage/computation/connectivity resources at the network "edge". To be cost-effective, a key functional requirement for such infrastructure is enabling the sharing of heterogeneous resources amongst tenants/service providers supporting spatially varying and dynamic user demands. This paper proposes a resource allocation criterion, namely, Share Constrained Slicing (SCS), for slices allocated predefined shares of the network's resources, which extends the traditional alpha-fairness criterion, by striking a balance among inter- and intra-slice fairness vs. overall efficiency. We show that SCS has several desirable properties including slice-level protection, envyfreeness, and load driven elasticity. In practice, mobile users' dynamics could make the cost of implementing SCS high, so we discuss the feasibility of using a simpler (dynamically) weighted max-min as a surrogate resource allocation scheme. For a setting with stochastic loads and elastic user requirements, we establish a sufficient condition for the stability of the associated coupled network system. Finally, and perhaps surprisingly, we show via extensive simulations that while SCS (and/or the surrogate weighted max-min allocation) provides inter-slice protection, they can achieve improved job delay and/or perceived throughput, as compared to other weighted max-min based allocation schemes whose intra-slice weight allocation is not share-constrained, e.g., traditional max-min or discriminatory processor sharing

Statistical Multiplexing and Traffic Shaping Games for Network Slicing

Next generation wireless architectures are expected to enable slices of shared wireless infrastructure which are customized to specific mobile operators/services. Given infrastructure costs and the stochastic nature of mobile services' spatial loads, it is highly desirable to achieve efficient statistical multiplexing amongst such slices. We study a simple dynamic resource sharing policy which allocates a 'share' of a pool of (distributed) resources to each slice-Share Constrained Proportionally Fair (SCPF). We give a characterization of SCPF's performance gains over static slicing and general processor sharing. We show that higher gains are obtained when a slice's spatial load is more 'imbalanced' than, and/or 'orthogonal' to, the aggregate network load, and that the overall gain across slices is positive. We then address the associated dimensioning problem. Under SCPF, traditional network dimensioning translates to a coupled share dimensioning problem, which characterizes the existence of a feasible share allocation given slices' expected loads and performance requirements. We provide a solution to robust share dimensioning for SCPF-based network slicing. Slices may wish to unilaterally manage their users' performance via admission control which maximizes their carried loads subject to performance requirements. We show this can be modeled as a 'traffic shaping' game with an achievable Nash equilibrium. Under high loads, the equilibrium is explicitly characterized, as are the gains in the carried load under SCPF vs. static slicing. Detailed simulations of a wireless infrastructure supporting multiple slices with heterogeneous mobile loads show the fidelity of our models and range of validity of our high load equilibrium analysis

Resource sharing in network slicing and human-machine interactions

In this thesis we explore two novel resource allocation models. The first addresses challenges associated with dynamic sharing of network resources by multiple tenants/services via network slicing. The second focuses on a data-driven approach to the optimization of resource allocation in interactive human-machine processes. In our first thrust we investigate how to allocate shared storage, computation, and/or connectivity resources distributed amongst multiple tenants/ virtual service providers which have dynamic loads. It is expected that next generation of wireless network will be shared by an increasing number of data-intensive mobile applications (e.g., autonomous cars, IoT, interactive 360° video streaming), and tenants/service providers. A key functional requirement for such infrastructure is enabling efficient sharing of heterogeneous resource among tenants/service providers supporting spatially varying and dynamic user demands, both from the point of view of enabling the deployment and performance management to diverse service providers and/or tenants, as well as means to increase utilization and reduce CAPEX/OPEX associated with deploying possible new infrastructures. To that end, we propose a novel dynamic resource sharing policy, namely, Share Constrained Proportional Fair (SCPF), which allocates a predefined ‘share’ of a pool of (distributed) resources to each slice. We provide a characterization of the achievable performance gains over General Processor Sharing (GPS), and Static Slicing (SS), i.e., fixed allocation of resources to slices. We also characterize the associated share dimensioning problem, asking when a particular set of load profiles and QoS requirements are feasible, as well as what should be an appropriate pricing strategy. We further consider possible slice-based admission control scheme where slices engage in an underlying game to maximize their carried loads subject to performance requirements. In order to accommodate settings where one would wish to provision different types of resources which are coupled through user demands, we generalize SCPF to a more general resource allocation criterion, namely, Share Constrained Slicing (SCS), which extends traditional α—fairness criterion, by striking a balance among inter- and intra-slice fairness vs. overall efficiency. We show that SCS has several desirable properties including slice-level protection, envyfreeness, and load-driven elasticity. In practice, mobile users' dynamics could make the cost of implementing SCS high, so we also study the feasibility of using a dynamically weighted max-min fair policy as a surrogate resource allocation scheme. For a setting with stochastic loads and elastic user requirements, we model the user dynamics under SCS as a queuing network and establish the stability condition. Finally, and perhaps surprisingly, we show via extensive simulation that while SCS (and/or the surrogate weighted max-min allocation) provides inter-slice protection, they can also achieve improved job delay and/or perceived throughput, as compared to other weighted max-min based allocation schemes whose intra-slice weight allocation is not share-constrained, e.g., traditional max-min and/or discriminatory processor sharing. In our second thrust we study how to optimize resource allocation in the context of human-machine interactions. Examples of such processes could include systems aimed at assisting humans in interactive learning, workload allocation, or web-search advertising. We devise an innovative framework to enable the optimization of a reward over an interactive process in a data-driven manner. This is a challenging problem for several reasons: (1) humans' behavior is not easily modeled and may reflect biases, memory and be sensitive to sequencing, all of which should/could be inferred from data; (2) because these interactions are typically sequential and transient, inferring such complex models for human behavior is difficult; (3) furthermore, in order to collect data on human-machine interactions one must choose a machine policy which in turn may bias inferences on human behavior. In this thesis we approach the problem of jointly estimating human behavior and optimizing machine policies via Alternating Entropy-Reward Ascent (AREA) algorithm. We characterize AREA in terms of its space and time complexity and convergence. We also provide an initial validation based on synthetic data generated by an established noisy nonlinear model for human decision-makingElectrical and Computer Engineerin

A Case Study of Edge Computing Implementations: Multi-access Edge Computing, Fog Computing and Cloudlet

With the explosive growth of intelligent and mobile devices, the current centralized cloud computing paradigm is encountering difficult challenges. Since the primary requirements have shifted towards implementing real-time response and supporting context awareness and mobility, there is an urgent need to bring resources and functions of centralized clouds to the edge of networks, which has led to the emergence of the edge computing paradigm. Edge computing increases the responsibilities of network edges by hosting computation and services, therefore enhancing performances and improving quality of experience (QoE). Fog computing, multi-access edge computing (MEC), and cloudlet are three typical and promising implementations of edge computing. Fog computing aims to build a system that enables cloud-to-thing service connectivity and works in concert with clouds, MEC is seen as a key technology of the fifth generation (5G) system, and Cloudlet is a micro-data center deployed in close proximity. In terms of deployment scenarios, Fog computing focuses on the Internet of Things (IoT), MEC mainly provides mobile RAN application solutions for 5G systems, and cloudlet offloads computing power at the network edge. In this paper, we present a comprehensive case study on these three edge computing implementations, including their architectures, differences, and their respective application scenario in IoT, 5G wireless systems, and smart edge. We discuss the requirements, benefits, and mechanisms of typical co-deployment cases for each paradigm and identify challenges and future directions in edge computing

5g new radio access and core network slicing for next-generation network services and management

In recent years, fifth-generation New Radio (5G NR) has attracted much attention owing to its potential in enhancing mobile access networks and enabling better support for heterogeneous services and applications. Network slicing has garnered substantial focus as it promises to offer a higher degree of isolation between subscribers with diverse quality-of-service requirements. Integrating 5G NR technologies, specifically the mmWave waveform and numerology schemes, with network slicing can unlock unparalleled performance so crucial to meeting the demands of high throughput and sub-millisecond latency constraints. While conceding that optimizing next-generation access network performance is extremely important, it needs to be acknowledged that doing so for the core network is equally as significant. This is majorly due to the numerous core network functions that execute control tasks to establish end-to-end user sessions and route access network traffic. Consequently, the core network has a significant impact on the quality-of-experience of the radio access network customers. Currently, the core network lacks true end-to-end slicing isolation and reliability, and thus there is a dire need to examine more stringent configurations that offer the required levels of slicing isolation for the envisioned networking landscape. Considering the factors mentioned above, a sequential approach is adopted starting with the radio access network and progressing to the core network. First, to maximize the downlink average spectral efficiency of an enhanced mobile broadband slice in a time division duplex radio access network while meeting the quality-of-service requirements, an optimization problem is formulated to determine the duplex ratio, numerology scheme, power, and bandwidth allocation. Subsequently, to minimize the uplink transmission power of an ultra-reliable low latency communications slice while satisfying the quality-of-service constraints, a second optimization problem is formulated to determine the above-mentioned parameters and allocations. Because 5G NR supports dual-band transmissions, it also facilitates the usage of different numerology schemes and duplex ratios across bands simultaneously. Both problems, being mixed-integer non-linear programming problems, are relaxed into their respective convex equivalents and subsequently solved. Next, shifting attention to aerial networks, a priority-based 5G NR unmanned aerial vehicle network (UAV) is considered where the enhanced mobile broadband and ultra-reliable low latency communications services are considered as best-effort and high-priority slices, correspondingly. Following the application of a band access policy, an optimization problem is formulated. The goal is to minimize the downlink quality-of-service gap for the best-effort service, while still meeting the quality-of-service constraints of the high-priority service. This involves the allocation of transmission power and assignment of resource blocks. Given that this problem is a mixed-integer nonlinear programming problem, a low-complexity algorithm, PREDICT, i.e., PRiority BasED Resource AllocatIon in Adaptive SliCed NeTwork, which considers the channel quality on each individual resource block over both bands, is designed to solve the problem with a more accurate accounting for high-frequency channel conditions. Transitioning to minimizing the operational latency of the core network, an integer linear programming problem is formulated to instantiate network function instances, assign them to core network servers, assign slices and users to network function instances, and allocate computational resources while maintaining virtual network function isolation and physical separation of the core network control and user planes. The actor-critic method is employed to solve this problem for three proposed core network operation configurations, each offering an added degree of reliability and isolation over the default configuration that is currently standardized by the 3GPP. Looking ahead to potential future research directions, optimizing carrier aggregation-based resource allocation across triple-band sliced access networks emerges as a promising avenue. Additionally, the integration of coordinated multi-point techniques with carrier aggregation in multi-UAV NR aerial networks is especially challenging. The introduction of added carrier frequencies and channel bandwidths, while enhancing flexibility and robustness, complicates band-slice assignments and user-UAV associations. Another layer of intriguing yet complex research involves optimizing handovers in high-mobility UAV networks, where both users and UAVs are mobile. UAV trajectory planning, which is already NP-hard even in static-user scenarios, becomes even more intricate to obtain optimal solutions in high-mobility user cases