Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geocast into the Past: Towards a Privacy-Preserving Spatiotemporal
  Multicast for Cellular Networks   This article introduces the novel concept of Spatiotemporal Multicast (STM),
which is the issue of sending a message to mobile devices that have been
residing at a specific area during a certain time span in the past. A wide
variety of applications can be envisioned for this concept, including crime
investigation, disease control, and social applications. An important aspect of
these applications is the need to protect the privacy of its users. In this
article, we present an extensive overview of applications and objectives to be
fulfilled by an STM service. Furthermore, we propose a first Cluster-based
Spatiotemporal Multicast (CSTM) approach and provide a detailed discussion of
its privacy features. Finally, we evaluate the performance of our scheme in a
large-scale simulation setup.

4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas