The present invention relates to compounds of formula I:or a pharmaceutically acceptable salt thereof, that inhibit bacterial gyrase andor Topo IV and pharmaceutically acceptable compositions comprising said compounds. After leasing a link to an operator device, a provider or operator may monitor the available capacity of the leased link and generate an advertising frame when the actual available capacity is below the defined leased capacity of the link. The reader system includes at least the first reader system and a second reader system with reader elements on the same head. The calculated values are stored in an encoded coordinates matrix and used to determine common segments.