Attack the relay can be brutal, but there are some strategies that make them easier. For me, it is having a concealed shinobi sighting the relay, and a sniper (or 2) at the edge of the map with line of sight to the relay and out of sight of all other enemies. Throw evac flair as soon as sniper starts shooting the relay, and most of the time, I complete the mission and evac without enemeies ever spotting me. Key of course is making sure shinobi stays concealed the whole time.



Without a sniper, I try to get in position to shot relay before engaging any enemies, prep an evac as soon as I engage, and hope I can both keep enemeies at bay and shot down the relay and evac as soon as I can. If I ever get 2 waves of reinforcements, probably means my plan failed.

Clever.

I think they are brutal on purpose as they are often the final gateway mission in the liberation chain before the network mission...which leads to the HQ assault. If you think 30 is bad, I just finished an HQ assault on veteran with 69 enemies killed. Stupid Sectoid Commander behind the front line kept raising half a dozen dead advent every other turn. Talk about slog...fun though!

I actually really enjoy HQ/Network Tower missions, but that is because I have felt that the "Assault the enemy" missions tend to feel extremely tightly balanced in comparison to this one type of infiltration mission.

Especially when the players supplies are getting raided. Those missions feel high concept and have always been extremely enjoyable in my time playing.

Alien Relay missions are the only ones I geniunely don't enjoy...
Now that I know they may be required to liberate regions, I am far more hesitent when it comes to actually continuing.

From my playthroughs it's been alien relays or rescue VIP missions that finally get you through to the network tower mission. So I suppose you could always just pass up the alien relays and wait for a VIP to show.

I sort of enjoy the alien relays missions though. It's a great first test to see if you have a team strong enough to defeat larger numbers of enemies. I usually just set up the evac right by the relay and put all of the team's firepower into the relay on one go, then book it out before things get too swarmy.

From what I can tell the alien relay missions are most difficult in that you tend to get a lot of reinforcements landing. The "bring a Sniper and nuke it" strategy is a little iffy because in my experience often it's hard to get a sightline to the Relay. My best advice is try and sneak within range of the Relay, set up a defensive position with smoke, and then call in evac and open up onto the Relay at the same time.

One note- any soldier shooting at the Relay has 100% chance to hit. This means that soldiers with awful aim can always contribute, and- more importantly- the Ranger's Sawed-Off Shotgun has 100% chance to hit from medium range. That tends to take out most of the Relay's health in one shot... something about 9-18 damage with Ballistic tech being good?

I do like ranger shotguns for killing them, its just....
It also tends to make every pod on the map run into sight.

lets put it this way the relay mission give you the least rewardout of all other mission and one extra thing to kill, and the fact you need to balance shoting the relay and the reinforcement makes the mission least worth while doing just skip if it is not long a long timer and low enemy units. even if it is long timer and low enemy units still consider skipping it cause it is almost never worth the risk.

@Ithuriel
Yes, that is the most promising strategy. the best way is to find a defensible rooftop from where you can be extracted and see the relay. Bringing shredder guns on exo suits helps a lot with getting line of sight.
(After having researched exo-suits I still wonder how I could get any mission done without them.)

AFAIK, the rnfs start when you are revealed, so try to avoid this until you have shots on the relay.
2 Tactics work for me.
1. sniper from the background with line of sight, shinobi spotts for him
2. 3-4 guys with shotguns, sneak up on it, throw the evac down, kill it within 1 turn and peace out

In general, I find one of the most important things is to stay concealed until you are in a positione to engage the objective the most important part on most missions