The Laws of Prayer /Shema (48)

1. The ideal time to read the Shema is just before sunrise (Hanetz Hachamah), so as to finish the Shem with the blessings at sunrise and start the Amidah at sunrise. One who can do this receives great reward. (Shulchan Aruch and Mishne Berurah 58)

2. If he did not read it before sunrise, he should read it as early as possible, as swift people do the commandments as soon as possible. However, this should not cause him to pray by himself, or without Tefillin. (ibid)