At the time when most of the service providers have either reduced their 3G tariff or are interested in doing so in near future, Mahanagar Telephone Nigam Limited (MTNL) is increasing in its Delhi circle.It is learned the carrier is revising its 3G browsing data rates to be effective from July 15th, 2012. Earlier the charges 3G users paid was 1p/Kb. MTNL has now raised it to 2p/Kb. Anyways, there is still a bit of relief to existing customers. They continue enjoying the old rates till January 26th, 2013. The carrier has also revised the rates of its weekly STD pack. It has been now increased to Rs 55 for users in Delhi circle. In this plan customers will get 135 STD minutes with 7 days validity period. Only 50 paisa talk time will be added in this pack.