Mobile telecommunications stocks are under pressure despite some cheery updates from the sector.Vodafone today cut the price of sending emails and surfing the net while abroad. The announcement has failed to impress the market though.Avanti Communications bucked the downward trend after the satellite operator's announcement that it successfully launched its HYLAS 1 satellite from the Kourou space centre in French Guiana on Friday.Top performing sectors so far todayAlternative Energy 3,488.55 +0.77%Bottom performing sectors so far todayIndustrial Metals & Mining 7,242.84 -3.49%Mobile Telecommunications 3,688.39 -2.76%Personal Goods 17,774.26 -2.58%Fixed Line Telecommunications 2,169.83 -2.49%Chemicals 6,182.73 -2.37%