diff --git a/src/prefix-announcement.cpp b/src/prefix-announcement.cpp
index 6149526..410d270 100644
--- a/src/prefix-announcement.cpp
+++ b/src/prefix-announcement.cpp
@@ -74,6 +74,7 @@
     dataName.appendVersion(version.value_or(time::toUnixTimestamp(time::system_clock::now()).count()));
     dataName.appendSegment(0);
     m_data.emplace(dataName);
+    m_data->setContentType(tlv::ContentType_PrefixAnn);
 
     Block content(tlv::Content);
     content.push_back(makeNonNegativeIntegerBlock(tlv::nfd::ExpirationPeriod,
@@ -116,4 +117,22 @@
   return *this;
 }
 
+bool
+operator==(const PrefixAnnouncement& lhs, const PrefixAnnouncement& rhs)
+{
+  return lhs.getAnnouncedName() == rhs.getAnnouncedName() &&
+         lhs.getExpiration() == rhs.getExpiration() &&
+         lhs.getValidityPeriod() == rhs.getValidityPeriod();
+}
+
+std::ostream&
+operator<<(std::ostream& os, const PrefixAnnouncement& pa)
+{
+  os << pa.getAnnouncedName() << " expires=" << pa.getExpiration();
+  if (pa.getValidityPeriod()) {
+    os << " validity=" << *pa.getValidityPeriod();
+  }
+  return os;
+}
+
 } // namespace ndn
diff --git a/src/prefix-announcement.hpp b/src/prefix-announcement.hpp
index d811230..6c48015 100644
--- a/src/prefix-announcement.hpp
+++ b/src/prefix-announcement.hpp
@@ -119,10 +119,29 @@
 private:
   mutable optional<Data> m_data;
   Name m_announcedName;
-  time::milliseconds m_expiration;
+  time::milliseconds m_expiration = 0_ms;
   optional<security::ValidityPeriod> m_validity;
 };
 
+/** \brief Test whether two prefix announcements has the same name, expiration period,
+ *         and validity period.
+ */
+bool
+operator==(const PrefixAnnouncement& lhs, const PrefixAnnouncement& rhs);
+
+inline bool
+operator!=(const PrefixAnnouncement& lhs, const PrefixAnnouncement& rhs)
+{
+  return !(lhs == rhs);
+}
+
+/** \brief Print prefix announcement to a stream.
+ *
+ *  This string is for debugging purpose. Its syntax is not public API.
+ */
+std::ostream&
+operator<<(std::ostream& os, const PrefixAnnouncement& pa);
+
 } // namespace ndn
 
 #endif // NDN_CXX_PREFIX_ANNOUNCEMENT_HPP
diff --git a/tests/unit-tests/prefix-announcement.t.cpp b/tests/unit-tests/prefix-announcement.t.cpp
index 1dff8f9..fa69eb3 100644
--- a/tests/unit-tests/prefix-announcement.t.cpp
+++ b/tests/unit-tests/prefix-announcement.t.cpp
@@ -45,36 +45,6 @@
     "     1720 0000000000000000000000000000000000000000000000000000000000000000"_block);
 }
 
-BOOST_FIXTURE_TEST_CASE(Encode, IdentityManagementFixture)
-{
-  PrefixAnnouncement pa;
-  BOOST_CHECK(!pa.getData());
-  const Data& data0 = pa.toData(m_keyChain, signingWithSha256(), 5);
-  BOOST_CHECK_EQUAL(data0.getName(), "/32=PA/%FD%05/%00%00");
-  BOOST_REQUIRE(pa.getData());
-  BOOST_CHECK_EQUAL(*pa.getData(), data0);
-
-  pa.setAnnouncedName("/net/example");
-  BOOST_CHECK_THROW(pa.setExpiration(-1_ms), std::invalid_argument);
-  pa.setExpiration(1_h);
-  const Data& data1 = pa.toData(m_keyChain, signingWithSha256(), 1);
-  BOOST_CHECK_EQUAL(data1.getName(), "/net/example/32=PA/%FD%01/%00%00");
-  const Block& payload1 = data1.getContent();
-  payload1.parse();
-  BOOST_CHECK_EQUAL(readNonNegativeInteger(payload1.get(tlv::nfd::ExpirationPeriod)), 3600000);
-  BOOST_CHECK(payload1.find(tlv::ValidityPeriod) == payload1.elements_end());
-
-  pa.setValidityPeriod(security::ValidityPeriod(time::fromIsoString("20181030T000000"),
-                                                time::fromIsoString("20181124T235959")));
-  const Data& data2 = pa.toData(m_keyChain);
-  const Block& payload2 = data2.getContent();
-  payload2.parse();
-  BOOST_CHECK_EQUAL(readNonNegativeInteger(payload2.get(tlv::nfd::ExpirationPeriod)), 3600000);
-  BOOST_CHECK_EQUAL(payload2.get(tlv::ValidityPeriod),
-                    "FD00FD26 FD00FE0F323031383130333054303030303030"
-                    "         FD00FF0F323031383131323454323335393539"_block);
-}
-
 BOOST_AUTO_TEST_CASE(DecodeGood)
 {
   Data data0 = makePrefixAnnData();
@@ -178,22 +148,97 @@
   BOOST_CHECK_THROW(PrefixAnnouncement pa7(data7), tlv::Error);
 }
 
+BOOST_FIXTURE_TEST_CASE(EncodeEmpty, IdentityManagementFixture)
+{
+  PrefixAnnouncement pa;
+  BOOST_CHECK(!pa.getData());
+  BOOST_CHECK_EQUAL(pa.getAnnouncedName(), "/");
+  BOOST_CHECK_EQUAL(pa.getExpiration(), 0_ms);
+  BOOST_CHECK(!pa.getValidityPeriod());
+
+  const Data& data = pa.toData(m_keyChain, signingWithSha256(), 5);
+  BOOST_CHECK_EQUAL(data.getName(), "/32=PA/%FD%05/%00%00");
+  BOOST_CHECK_EQUAL(data.getContentType(), tlv::ContentType_PrefixAnn);
+  BOOST_REQUIRE(pa.getData());
+  BOOST_CHECK_EQUAL(*pa.getData(), data);
+
+  PrefixAnnouncement decoded(data);
+  BOOST_CHECK_EQUAL(decoded.getAnnouncedName(), "/");
+  BOOST_CHECK_EQUAL(decoded.getExpiration(), 0_s);
+  BOOST_CHECK(!decoded.getValidityPeriod());
+
+  BOOST_CHECK_EQUAL(pa, decoded);
+}
+
+BOOST_FIXTURE_TEST_CASE(EncodeNoValidity, IdentityManagementFixture)
+{
+  PrefixAnnouncement pa;
+  pa.setAnnouncedName("/net/example");
+  BOOST_CHECK_THROW(pa.setExpiration(-1_ms), std::invalid_argument);
+  pa.setExpiration(1_h);
+
+  const Data& data = pa.toData(m_keyChain, signingWithSha256(), 1);
+  BOOST_CHECK_EQUAL(data.getName(), "/net/example/32=PA/%FD%01/%00%00");
+  BOOST_CHECK_EQUAL(data.getContentType(), tlv::ContentType_PrefixAnn);
+
+  const Block& payload = data.getContent();
+  payload.parse();
+  BOOST_CHECK_EQUAL(readNonNegativeInteger(payload.get(tlv::nfd::ExpirationPeriod)), 3600000);
+  BOOST_CHECK(payload.find(tlv::ValidityPeriod) == payload.elements_end());
+
+  PrefixAnnouncement decoded(data);
+  BOOST_CHECK_EQUAL(decoded.getAnnouncedName(), "/net/example");
+  BOOST_CHECK_EQUAL(decoded.getExpiration(), 1_h);
+  BOOST_CHECK(!decoded.getValidityPeriod());
+
+  BOOST_CHECK_EQUAL(pa, decoded);
+}
+
+BOOST_FIXTURE_TEST_CASE(EncodeWithValidity, IdentityManagementFixture)
+{
+  PrefixAnnouncement pa;
+  pa.setAnnouncedName("/net/example");
+  pa.setExpiration(1_h);
+  security::ValidityPeriod validity(time::fromIsoString("20181030T000000"),
+                                    time::fromIsoString("20181124T235959"));
+  pa.setValidityPeriod(validity);
+
+  const Data& data = pa.toData(m_keyChain);
+  const Block& payload = data.getContent();
+  payload.parse();
+  BOOST_CHECK_EQUAL(readNonNegativeInteger(payload.get(tlv::nfd::ExpirationPeriod)), 3600000);
+  BOOST_CHECK_EQUAL(payload.get(tlv::ValidityPeriod), validity.wireEncode());
+
+  PrefixAnnouncement decoded(data);
+  BOOST_CHECK_EQUAL(decoded.getAnnouncedName(), "/net/example");
+  BOOST_CHECK_EQUAL(decoded.getExpiration(), 1_h);
+  BOOST_REQUIRE(decoded.getValidityPeriod());
+  BOOST_CHECK_EQUAL(*decoded.getValidityPeriod(), validity);
+
+  BOOST_CHECK_EQUAL(pa, decoded);
+}
+
 BOOST_AUTO_TEST_CASE(Modify)
 {
-  PrefixAnnouncement pa0(makePrefixAnnData());
+  PrefixAnnouncement pa(makePrefixAnnData());
+
+  PrefixAnnouncement pa0(pa);
   BOOST_REQUIRE(pa0.getData());
   BOOST_CHECK_EQUAL(*pa0.getData(), makePrefixAnnData());
   pa0.setAnnouncedName("/com/example");
   BOOST_CHECK(!pa0.getData());
+  BOOST_CHECK_NE(pa0, pa);
 
   PrefixAnnouncement pa1(makePrefixAnnData());
   pa1.setExpiration(5_min);
   BOOST_CHECK(!pa1.getData());
+  BOOST_CHECK_NE(pa1, pa);
 
   PrefixAnnouncement pa2(makePrefixAnnData());
   pa2.setValidityPeriod(security::ValidityPeriod(time::fromIsoString("20180118T000000"),
                                                  time::fromIsoString("20180212T235959")));
   BOOST_CHECK(!pa2.getData());
+  BOOST_CHECK_NE(pa2, pa);
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestPrefixAnnouncement