Abstract: High Frequency (HF) communication systems use radio waves at frequencies in the range of 3-30 MHz propagating in the form of skywave with the help of the ionosphere. For emergency ...

These contact details are only for journalists wishing to contact the BBC with enquiries. For all other queries please see the BBC Contact page. LZ – Laura Zetterberg – laura.zetterberg@bbc.co.uk ...

These contact details are only for journalists wishing to contact the BBC with enquiries. For all other queries please see the BBC Contact page.

Pakistan Cricket Board and its Anti Corruption Unit are in the process of reviewing reports regarding the alleged involvement of cricketer Hasan Raza in Corrupt Conduct as reported in a programme of ...