Since 2010 Russia has finally been able to replace many of its Cold War era electronic warfare aircraft with modern equipment. The Cold War era aircraft was based on military versions of the four engine turboprop Il-10 airliner. The most visible of these was the 66 ton Il-38, which was the Russian answer to the American P-3 anti-submarine aircraft. Like the Americans and other Western nations the Russians replaced the four engine Cold War era aircraft with more modern twin engine jet airliners.
Russia used the Tu-204 for its new electronic warfare aircraft. This two engine jet can carry up to 210 passengers, or 21 tons of cargo. The Tu-204 weighs about 100 tons, and can fly 4,000 kilometers per hop. It is a relatively inexpensive airliner in its class, costing less than $50 million each. The military version is called the Tu-214. This model comes with more cargo doors and can easily be modified to carry more fuel for longer range or greater endurance. Like the Il-10 there will be several different military versions of the Tu-214.
So far these Tu-214s have rarely been seen outside Russia. One exception was a Tu-214R that recently showed up in Syria. This is the Russian equivalent of the American RC-135 Rivet Joint. These aircraft can collect a wide variety of electronic signals in an area, and analyze them quickly and act (as in using onboard jammers). The analysis effort is looking for patterns. The enemy below leaves signs electronically (cell phones, walkie-talkies) or visually (images captured on surveillance cameras). Using the right math and analytical tools (software and computers) and you can quickly discover where the bad guys are coming from, and have the ground troops promptly shell, bomb or raid the location. This kind of work was popular with the RC-135 crews (about thirty aircrew and techies) in Iraq, Afghanistan (and elsewhere), because they were getting a chance to do, in a combat zone, what they have long trained for. Moreover, it's relatively risk free, as the aircraft fly beyond the range of machine-gun or shoulder fired anti-aircraft missiles. In addition, the most productive work is done during night missions, when the bad guys can't even see the RC-135's (or Tu-214R) high above.
Russia and China both studied the use of RC-135s in Iraq and Afghanistan and the Russian response was two Tu-214Rs. These aircraft completed their testing during 2015 and the one in Syria is getting its first combat experience. There are at least seven other Tu-214s in military service for surveillance, communications or as command posts.