Telecom operator Sistema Shyam Teleservices (SSTL), which offers services under MTS brand, has signed a three-year managed services deal with networking gear maker Ericsson for four circles. These circles include Uttar Pradesh East and West, Gujarat and Rajasthan. As per the agreement, Ericsson will be responsible for network optimisation; operations and maintenance including field operations and 24/7 network service assurance, a joint statement said. The contract also includes management of fibre transport and wireline networks in Rajasthan as well as network service provisioning, customer problem management and spare parts management, the statement added.SSTL is a joint venture between Russia' s Sistema, the Russian Federation and the Shyam Group (India). It offers CDMA services and has over 11 million wireless subscribers.