Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Survey on High-Speed Railway Communications: A Radio Resource
  Management Perspective   High-speed railway (HSR) communications will become a key feature supported
by intelligent transportation communication systems. The increasing demand for
HSR communications leads to significant attention on the study of radio
resource management (RRM), which enables efficient resource utilization and
improved system performance. RRM design is a challenging problem due to
heterogenous quality of service (QoS) requirements and dynamic characteristics
of HSR wireless communications. The objective of this paper is to provide an
overview on the key issues that arise in the RRM design for HSR wireless
communications. A detailed description of HSR communication systems is first
presented, followed by an introduction on HSR channel models and
characteristics, which are vital to the cross-layer RRM design. Then we provide
a literature survey on state-of-the-art RRM schemes for HSR wireless
communications, with an in-depth discussion on various RRM aspects including
admission control, mobility management, power control and resource allocation.
Finally, this paper outlines the current challenges and open issues in the area
of RRM design for HSR wireless communications.

10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn