The development of large language models (LLMs) has catalyzed unprecedented demand on the computing network, specifically for large-scale, few-hops, and low-latency, which directly underpin LLM task efficiency. However, mainstream topologies such as Clos suffer from costs and latency, while topologies with good scalability have symmetric or collective communication issues. In order to achieve a favorable balance among design metrics, we propose a novel topology named the Balanced Sparse Tree (BST), which is a topology characterized by symmetric design and sparse connections, motivated by hypergraph theory and Steiner Systems. Its degree-diameter upper-bound approaches the Moore Bound for Bipartite Biregular graphs, larger than other known dia-meter-2 topologies. Furthermore, we incorporate differentiated routing, deadlock freedom, and topology-affined deployment into BST. Testbed experiments, simulations, together with modeling analysis, demonstrate the superiority of BST over the state-of-the-art in network scale, latency, bandwidth, and cost. With equivalent scales, BST outperforms Clos with a 50% cost reduction while maintaining comparable performance for AI workloads. Furthermore, BST delivers a 3.9%–11.8% gain in collective communications and has 13.4% improvement over state-of-the-art topologies.

Wireless Charging Vehicles (WCVs) have been widely explored as a means of enabling continuous operation of sensors that are powered by batteries. However, the energy consumption of WCVs can be inefficient, leading to insufficient energy supply for sensors that are located in challenging-to-access areas. Consequently, there is a need to design an effective charging and energy sharing scheme for sensors to improve the quality of service in this setup. This paper focuses on the Joint optimization of Mobile charging and Energy sharing of sensors (JOIN-ME) problem, which is known to be NP-hard. To address this challenge, we first transform JOIN-ME into a submodular maximization problem with general constraints. Subsequently, we propose the Routing planning, Mobile charging, and Energy sharing for Sensing devices (RMES) algorithm, which has an approximation ratio of 1/8(1-1/e). Finally, we conduct experiments to showcase the superior performance of RMES compared to existing baselines, under varying scales and constraints. Our work on the design of an efficient charging and energy sharing scheme for sensors can significantly improve the reliability and longevity of wireless sensor networks, enabling the deployment of these networks in critical applications such as environmental monitoring, crowd sensing, and security surveillance.

Cloud computing develops rapidly in recent years and provides service to many applications, in which job scheduling becomes more and more important to improve the quality of service. Parallel processing on cloud requires different machines starting simultaneously on the same job and brings processing slowdown due to communications overhead, defined as synchronization constraint and parallel slowdown. This paper investigates a new job scheduling problem of makespan minimization on uniform machines and identical machines with synchronization constraint and parallel slowdown. We first conduct complexity analysis proving that the problem is difficult in the face of adversarial job allocation. Then we propose a novel job scheduling algorithm, United Wrapping Scheduling (UWS), and prove that UWS admits an O(logm)-approximation for makespan minimization over m uniform machines. For the special case of identical machines, UWS is simplified to Sequential Allocation, Refilling and Immigration algorithm (SARI), proved to have a constant approximation ratio of 8 (tight up to a factor of 4). Performance evaluation implies that UWS and SARI have better makespan and realistic approximation ratio of 2 compared to baseline methods United-LPT and FIFO, and lower bounds.