  Linear colliders are an attractive platform to explore high-precision physics
of newly discovered particles. The recent significant progress in advanced
accelerator technologies has motivated their applications to colliders which
has been discussed in the {\sc alegro} workshop. In this paper we discuss one
promising scheme, collinear wakefield acceleration. We especially discuss
available drive and witness beam sources based on L and S-band radiofrequency
technology, and also summarize available and forthcoming longitudinal shaping
techniques to improve the overall acceleration efficiency via the transformer
ratio.
