Time Machine on a local drive, then make that drive a network drive (via Server.app) on a different computer
This MacSales article covers how to do this very well: 

http://blog.macsales.com/18406-speed-time-machine-past-88mph-over-your-local-network

Essentially, you start with a fresh Time Machine backup. Start it on Wifi, then stop it, as it begins to backup files. This basically establishes the Time Machine archive. Then you attach your hard drive (or laptop) to the wired network, and resume backup. Once you have the initial backup done over the much faster wired network, subsequent backups will be much faster, as the are much smaller.

You establish the initial Backup over wifi because Time Machine does things differently over wifi vs directly connected. 

In any case, best of luck to you: I have never managed to get Time Machine to work reliably over wifi, and especially if you tend allow your Mac to go to sleep during a Time Machine backup (shut the lid for example)