J Sutaria, S Nanjundeswaran, B Gustafson… - US Patent …, 2011 - Google Patents
4,531,020 A 7/1985 Wechselberger et al. Thus, subscribers can be billed for enabled data
access ser 4,807,182 A 2/1989 Queen 4,831,582 A 5, 1989 Miller et al. vices and services …