Sun outage periods, with a duration of 15 days, generally occur twice every year when there is interruption in geostationary satellite signals caused by interference from solar radiation.
The bourses have been informed by the Indian Space Research Organization (ISRO) that there would be 'sun outage' from March 5 to March 18, 2013, between 1100 hrs to 1135 hrs.
In a circular, NSE said its trading members in capital market, Future & Option and currency derivative segments might face connectivity problems at different times on different dates based on their geographical location during this period.
Earlier, stock exchanges have been suspending trading for about 40 minutes on these 'sun outage' days due to the disruptions in satellite signals causing problems in the transmissions between trading terminals and trading platforms.
However, the trading would continue uninterrupted during the upcoming 'sun outage' period, NSE said, while asking the brokers to use alternative mode of connectivity instead of VSAT during this period.
VSATs (Very Small Aperture Terminals) are two-way satellite ground stations and access satellites in to relay data from small remote earth stations to other terminals or master earth station hubs.
The trading members, who do not have any alternate arrangement to VSAT and experience any difficulty, have been asked by NSE to log-out and re-login after the outage period.
Market regulator Sebi had sought in 2008 continuation of trading in normal course even during the sun outage period through alternative connectivity modes. The alternatives include leased lines and internet-based trading platforms.
NSE in December 2008 had asked its member brokers to put in place necessary alternative arrangements by the end of February 2009.