diff --git a/CMakeLists.txt b/CMakeLists.txt
index e7d9a01..278ec5c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -67,6 +67,9 @@ add_library(solanaceae_sha1_ngcft1
 	./solanaceae/ngc_ft1_sha1/participation.hpp
 	./solanaceae/ngc_ft1_sha1/participation.cpp
 
+	./solanaceae/ngc_ft1_sha1/re_announce_systems.hpp
+	./solanaceae/ngc_ft1_sha1/re_announce_systems.cpp
+
 	./solanaceae/ngc_ft1_sha1/chunk_picker_systems.hpp
 	./solanaceae/ngc_ft1_sha1/chunk_picker_systems.cpp
 
diff --git a/solanaceae/ngc_ft1_sha1/components.cpp b/solanaceae/ngc_ft1_sha1/components.cpp
index ba31d3a..26c6e82 100644
--- a/solanaceae/ngc_ft1_sha1/components.cpp
+++ b/solanaceae/ngc_ft1_sha1/components.cpp
@@ -25,6 +25,25 @@ bool FT1ChunkSHA1Cache::haveChunk(const SHA1Digest& hash) const {
 	return false;
 }
 
+void ReAnnounceTimer::set(const float new_timer) {
+	timer = new_timer;
+	last_max = new_timer;
+}
+
+void ReAnnounceTimer::reset(void) {
+	if (last_max <= 0.01f) {
+		last_max = 1.f;
+	}
+
+	last_max *= 2.f;
+	timer = last_max;
+}
+
+void ReAnnounceTimer::lower(void) {
+	timer *= 0.1f;
+	last_max *= 0.1f;
+}
+
 void TransferStatsTally::Peer::trimSent(const float time_now) {
 	while (recently_sent.size() > 4 && time_now - recently_sent.front().time_point > 1.f) {
 		recently_sent.pop_front();
diff --git a/solanaceae/ngc_ft1_sha1/components.hpp b/solanaceae/ngc_ft1_sha1/components.hpp
index ca81241..740a46c 100644
--- a/solanaceae/ngc_ft1_sha1/components.hpp
+++ b/solanaceae/ngc_ft1_sha1/components.hpp
@@ -75,6 +75,23 @@ namespace Components {
 		float timer {0.f};
 	};
 
+	struct AnnounceTargets {
+		entt::dense_set<Contact3> targets;
+	};
+
+	struct ReAnnounceTimer {
+		float timer {0.f};
+		float last_max {0.f};
+
+		void set(const float new_timer);
+
+		// exponential back-off
+		void reset(void);
+
+		// on peer join to group
+		void lower(void);
+	};
+
 	struct DownloadPriority {
 		// download/retreival priority in comparison to other objects
 		// not all backends implement this
diff --git a/solanaceae/ngc_ft1_sha1/re_announce_systems.cpp b/solanaceae/ngc_ft1_sha1/re_announce_systems.cpp
new file mode 100644
index 0000000..124baa0
--- /dev/null
+++ b/solanaceae/ngc_ft1_sha1/re_announce_systems.cpp
@@ -0,0 +1,83 @@
+#include "./re_announce_systems.hpp"
+
+#include "./components.hpp"
+#include <solanaceae/message3/components.hpp>
+#include <solanaceae/tox_contacts/components.hpp>
+#include <solanaceae/ngc_ft1/ngcft1_file_kind.hpp>
+#include <vector>
+#include <cassert>
+
+namespace Systems {
+
+void re_announce(
+	ObjectRegistry& os_reg,
+	Contact3Registry& cr,
+	NGCEXTEventProvider& neep,
+	const float delta
+) {
+	std::vector<Object> to_remove;
+	os_reg.view<Components::ReAnnounceTimer>().each([&os_reg, &cr, &neep, &to_remove, delta](Object ov, Components::ReAnnounceTimer& rat) {
+		ObjectHandle o{os_reg, ov};
+		// if paused -> remove
+		if (o.all_of<Message::Components::Transfer::TagPaused>()) {
+			to_remove.push_back(ov);
+			return;
+		}
+
+		// if not downloading or info incomplete -> remove
+		if (!o.all_of<Components::FT1ChunkSHA1Cache, Components::FT1InfoSHA1Hash, Components::AnnounceTargets>()) {
+			to_remove.push_back(ov);
+			assert(false && "transfer in broken state");
+			return;
+		}
+
+		if (o.get<Components::FT1ChunkSHA1Cache>().have_all) {
+			// transfer done, we stop announcing
+			to_remove.push_back(ov);
+			return;
+		}
+
+
+		// update all timers
+		rat.timer -= delta;
+
+		// send announces
+		if (rat.timer <= 0.f) {
+			rat.reset(); // exponential back-off
+
+			std::vector<uint8_t> announce_id;
+			const uint32_t file_kind = static_cast<uint32_t>(NGCFT1_file_kind::HASH_SHA1_INFO);
+			for (size_t i = 0; i < sizeof(file_kind); i++) {
+				announce_id.push_back((file_kind>>(i*8)) & 0xff);
+			}
+			assert(o.all_of<Components::FT1InfoSHA1Hash>());
+			const auto& info_hash = o.get<Components::FT1InfoSHA1Hash>().hash;
+			announce_id.insert(announce_id.cend(), info_hash.cbegin(), info_hash.cend());
+
+			for (const auto cv : o.get<Components::AnnounceTargets>().targets) {
+				if (cr.all_of<Contact::Components::ToxGroupPeerEphemeral>(cv)) {
+					// private ?
+					const auto [group_number, peer_number] = cr.get<Contact::Components::ToxGroupPeerEphemeral>(cv);
+					neep.send_pc1_announce(group_number, peer_number, announce_id.data(), announce_id.size());
+				} else if (cr.all_of<Contact::Components::ToxGroupEphemeral>(cv)) {
+					// public
+					const auto group_number = cr.get<Contact::Components::ToxGroupEphemeral>(cv).group_number;
+					neep.send_all_pc1_announce(group_number, announce_id.data(), announce_id.size());
+				} else {
+					assert(false && "we dont know how to announce to this target");
+				}
+			}
+		}
+	});
+
+	for (const auto ov : to_remove) {
+		os_reg.remove<Components::ReAnnounceTimer>(ov);
+		// we keep the annouce target list around (if it exists)
+		// TODO: should we make the target list more generic?
+	}
+
+	// TODO: how to handle unpause?
+}
+
+} // Systems
+
diff --git a/solanaceae/ngc_ft1_sha1/re_announce_systems.hpp b/solanaceae/ngc_ft1_sha1/re_announce_systems.hpp
new file mode 100644
index 0000000..46847f3
--- /dev/null
+++ b/solanaceae/ngc_ft1_sha1/re_announce_systems.hpp
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <solanaceae/object_store/object_store.hpp>
+#include <solanaceae/contact/contact_model3.hpp>
+#include <solanaceae/ngc_ext/ngcext.hpp>
+
+namespace Systems {
+
+void re_announce(
+	ObjectRegistry& os_reg,
+	Contact3Registry& cr,
+	NGCEXTEventProvider& neep,
+	const float delta
+);
+
+} // Systems
+
diff --git a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
index ab146f1..d4c0074 100644
--- a/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
+++ b/solanaceae/ngc_ft1_sha1/sha1_ngcft1.cpp
@@ -23,6 +23,7 @@
 #include "./chunk_picker.hpp"
 #include "./participation.hpp"
 
+#include "./re_announce_systems.hpp"
 #include "./chunk_picker_systems.hpp"
 #include "./transfer_stats_systems.hpp"
 
@@ -289,6 +290,8 @@ float SHA1_NGCFT1::iterate(float delta) {
 		}
 	}
 
+	Systems::re_announce(_os.registry(), _cr, _neep, delta);
+
 	{ // send out bitsets
 		// currently 1 per tick
 		if (!_queue_send_bitset.empty()) {
@@ -531,33 +534,21 @@ bool SHA1_NGCFT1::onEvent(const Message::Events::MessageUpdated& e) {
 
 	ce.emplace<Message::Components::Transfer::File>(std::move(file_impl));
 
-	// announce we are participating
+	// queue announce we are participating
 	// since this is the first time, we publicly announce to all
 	if (e.e.all_of<Message::Components::ContactFrom, Message::Components::ContactTo>()) {
 		const auto c_f = e.e.get<Message::Components::ContactFrom>().c;
 		const auto c_t = e.e.get<Message::Components::ContactTo>().c;
 
-		std::vector<uint8_t> announce_id;
-		const uint32_t file_kind = static_cast<uint32_t>(NGCFT1_file_kind::HASH_SHA1_INFO);
-		for (size_t i = 0; i < sizeof(file_kind); i++) {
-			announce_id.push_back((file_kind>>(i*8)) & 0xff);
-		}
-		assert(ce.all_of<Components::FT1InfoSHA1Hash>());
-		const auto& info_hash = ce.get<Components::FT1InfoSHA1Hash>().hash;
-		announce_id.insert(announce_id.cend(), info_hash.cbegin(), info_hash.cend());
-
 		if (_cr.all_of<Contact::Components::ToxGroupEphemeral>(c_t)) {
 			// public
-			const auto group_number = _cr.get<Contact::Components::ToxGroupEphemeral>(c_t).group_number;
-
-			_neep.send_all_pc1_announce(group_number, announce_id.data(), announce_id.size());
+			ce.get_or_emplace<Components::AnnounceTargets>().targets.emplace(c_t);
 		} else if (_cr.all_of<Contact::Components::ToxGroupPeerEphemeral>(c_f)) {
 			// private ?
-			const auto [group_number, peer_number] = _cr.get<Contact::Components::ToxGroupPeerEphemeral>(c_f);
-
-			_neep.send_pc1_announce(group_number, peer_number, announce_id.data(), announce_id.size());
+			ce.get_or_emplace<Components::AnnounceTargets>().targets.emplace(c_f);
 		}
 	}
+	ce.get_or_emplace<Components::ReAnnounceTimer>(0.1f, 60.f*(_rng()%5120) / 1024.f).timer = (_rng()%512) / 1024.f;
 
 	ce.remove<Message::Components::Transfer::TagPaused>();