There are no set minimum requirements. The offers of graduate admission depend on several factors including previous coursework and performance therein, previous research/industrial experience, GRE/TOEFL scores, recommendation letters, area of concentration and the department needs. You may apply to either the MS or the PhD program though requirements for admission to the latter are obviously much higher.
For international applicants, TOEFL and GRE scores are required for admission into our graduate programs. For domestic students, GRE scores are welcome (in fact, recommended) though not required and will be considered in the admission process if submitted.
There is no formal deadline for submitting applications for admission to the graduate programs in Electrical & Computer Engineering. Applications are processed as they are received. However, keep in mind that most of the GTA / GRA offer decisions are made in March and April for the upcoming Fall semester admissions. Therefore, applications should be submitted by February 15 if you want to be considered for the first round of GTA / GRA offers.