ITU‐T's Technical Reports and Specifications 245 Figure 28 – Example installation From an environmental point of view, to consume less electricity: It is required to consume less electricity per unit amount of transmission of data in order to reduce the environmental burden. It is also required to use less electricity when some data is transmitted along the same distance. It is preferable to be able to obtain electricity autonomously using natural energy such as wind power and energy from sunlight. To be small and lightweight: It is required to be easily installed and used for temporary radio relays or live broadcast from the events sites as well as the means of rapid network recovery in emergency where mobility characteristic is required. It is preferable to be able to lessen the number of component parts or the amount of volume to contain in order to reduce the environmental burden. For example, impulse radio wireless technology allows the system not to use oscillators which are likely to be large‐size. Connectivity to Internet Internet connections through the many access networks listed before, are a solution for SSC data transmission. As security is an extremely important element, Virtual Private Networks (VPN) are necessary to send data over the Internet. Encryption in these VPN is vital for the safe transport of data. A VPN is a private network in logical terms, mounted potentially on a shared medium. The Internet solution is a very economical option compared to using private channels from MPLS or Ethernet networks, but depends on the speed and availability of broadband Internet access. The Virtual Private Network (VPN) perfectly fits the requirements: security, data encryption, transparency and lower monthly costs. Tasks that must satisfy a VPN are: Remote access to databases, servers, etc. Authentication of both ends of the connection (main office and remote office). Ability to send IP packets through a tunnel in the public network (Internet), so that the two segments of the network interconnecting remote LAN does not appear to be geographically separated.