Social media networks have become the primary link for connecting the millennial generation to non-profits and other charity organizations.
We then address random contacts by public activity and age assortativity (the tendency for like age to assort with like) both for primary links in groups and for random contacts.
There is very strong assortativity by age for primary links within groups, and to a lesser extent for random contacts encountered within public activities.
Spectrum status which has the channel allocation for primary links.
In this scheme, the cognitive relay opportunistically switches among three different working modes, that is, Relay for Primary Link (RPL), Relay for Secondary Link (RSL), or Relay for Neither of the Links (RNL), respectively, based on the channel-dependent observation of both systems.
We can further reduce the burden of such calculation such that just simple calculation and feedback information is needed for both primary links and secondary users, which is desirable in practical scenarios.
Of the 68 primary links on the MSN.com home page, for example, 24 lead directly to "buy now" pages -- including some, nestled among noncommercial headlines, that seem deliberately designed to mislead, like "Tech, Trends, & Toys Pocket-sizee tech toys".
In terms of the number of different people within one's social contact network, the discrepancy is further magnified because primary links are sometimes duplicated across groups (for instance, some primary links within a friend group may be repeated in a sport group).
The SINR requirements of secondary links and primary links are posed in (6) and (7) where α and β are the SINR thresholds for the secondary network and the primary network, respectively.
In this paper, we assume that the global CSI of the main links, the eavesdropper's links, and primary link is available for evaluating the secrecy rate in the information receiver, which is a common assumption in the literature on physical layer security.
