...implementations use built-in browser-based encryption, but they also require a gateway between the WAP network and the standardnetwork. Encrypted messages must be decrypted for part of the journey so that they can be routed across the gateway...
http://www.computerweekly.com/Articles/2002/02/19/185255/3g-or-not-3g.htm
...resulting in less than 100% RPO. The significant advantages of this model include the lower cost of using a single, standardnetwork for both cluster and DR traffic, as well as enhanced flexibility and consistency with HP multi-OS environments...
http://www.computerweekly.com/DowntimePDF/pdf/4AA0_6737ENW.pdf