Planning Commission Deputy Chairman Montek Singh Ahluwalia today said the decision of the Reserve Bank to raise interest rates is a signal to bring inflation under control. He said the rate hike is within a range that is not unreasonable.Mr. Ahluwalia also expressed optimism that inflation will come down, in view of softening of prices across the globe, and a good harvest expected this year. About the impact of the decline in the value of the rupee against the dollar, on the economy, he said the country's foreign exchange reserves are very high, and he does not see any panic effect.