Call-fail-safe method for wireless traffic distribution across bands

Abstract

This invention presents an efficient and efficacious method for an equitable distribution of wireless traffic across the 800 and 1900 MHz bands. Even though traffic distribution across bands is desirable, there is a risk of call failure because of location of the mobile in the vicinity of a BTS group with low capacity in the other band. The method proposed here tells how decisions to migrate calls across bands can be made robust against call failures without imposing unreasonable constraints that make such decisions sparing. It presents: (i) a simple and effective quality measure for carrier-to-carrier comparison; (ii) convergence criteria flagging the convergence of the best carrier determination process for each BTS site using the afore mentioned quality measure; (iii) an effective procedure for their implementation; (iv) a decision procedure for selection of the band and carrier for call setup based on the best carriers of individual sites within the possible reach of the mobile in the two bands; and (v) an overall method that makes use of these components. It also presents method of extending this invention to next generation wireless systems that possibly operate in more than two frequency bands.