Ad Hoc Networking With Cost-Effective Infrastructure: Generalized Capacity Scaling

Capacity scaling of a large hybrid network with unit node density, consisting of n wireless ad hoc nodes, base stations (BSs) equipped with multiple antennas, and one remote central processor (RCP), is analyzed when wired backhaul links between the BSs and the RCP are rate-limited. We deal with a general scenario where the number of BSs, the number of antennas at each BS, and the backhaul link rate can scale at arbitrary rates relative to n (i.e., we introduce three scaling parameters). We first derive the minimum backhaul link rate required to achieve the same capacity scaling law as in the infinite-capacity backhaul link case. Assuming an arbitrary rate scaling of each backhaul link, a generalized achievable throughput scaling law is then analyzed in the network based on using one of pure multihop, hierarchical cooperation, and two infrastructure-supported routing protocols, and moreover, three-dimensional information-theoretic operating regimes are explicitly identified according to the three scaling parameters. In particular, we show the case where our network having a power limitation is also fundamentally in the degrees-of-freedomor infrastructure-limited regime, or both. In addition, a generalized cut-set upper bound under the network model is derived by cutting not only the wireless connections but also the wired connections. It is shown that our upper bound matches the achievable throughput scaling even under realistic network conditions such that each backhaul link rate scales slower than the aforementioned minimum-required backhaul link rate. Index Terms Achievability, backhaul link, base station (BS), cut-set upper bound, general capacity scaling, hybrid network, infrastructure, remote central processor (RCP). This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (MSIP) (2012R1A1A1044151), and by the MSIP, Korea in the ICT R&D Program 2013. C. Jeong is with the DMC R&D Center, Samsung Electronics, Suwon 443-742, Republic of Korea (E-mail: [email protected]). W.-Y. Shin is with the Department of Computer Science and Engineering, Dankook University, Yongin 448-701, Republic of Korea (E-mail: [email protected]). SUBMITTED TO IEEE TRANSACTIONS ON INFORMATION THEORY 2