As if NFC weren’t under enough pressure already in its battle to be the mobile payments standard, it now faces a new challenge, from chip giant MediaTek. The Taiwanese vendor has invented an alternative proximity-based technology called Hotknot. This could support similar applications to NFC, allowing handsets to be touched on readers, or one another, to make payments and exchange data. The company is seeking to get HotKnot embedded into cellphones, initially leveraging its strong presence in the Chinese vendor ecosystem, and then perhaps looking to establish an international standard. For now, it remains heavily focused on the Chinese market, and that country, of course, has a long tradition of trying to set its own wireless standards, often with limited…