diff --git a/core/java/android/net/NetworkStatsHistory.java b/core/java/android/net/NetworkStatsHistory.java
index 45d8e27645..5edbf5830d 100644
--- a/core/java/android/net/NetworkStatsHistory.java
+++ b/core/java/android/net/NetworkStatsHistory.java
@@ -133,6 +133,18 @@ public class NetworkStatsHistory implements Parcelable {
         }
     }
 
+    /**
+     * Record an entire {@link NetworkStatsHistory} into this history. Usually
+     * for combining together stats for external reporting.
+     */
+    public void recordEntireHistory(NetworkStatsHistory input) {
+        for (int i = 0; i < input.bucketCount; i++) {
+            final long start = input.bucketStart[i];
+            final long end = start + input.bucketDuration;
+            recordData(start, end, input.rx[i], input.tx[i]);
+        }
+    }
+
     /**
      * Ensure that buckets exist for given time range, creating as needed.
      */
@@ -202,6 +214,34 @@ public class NetworkStatsHistory implements Parcelable {
         }
     }
 
+    /**
+     * Return interpolated data usage across the requested range. Interpolates
+     * across buckets, so values may be rounded slightly.
+     */
+    public void getTotalData(long start, long end, long[] outTotal) {
+        long rx = 0;
+        long tx = 0;
+
+        for (int i = bucketCount - 1; i >= 0; i--) {
+            final long curStart = bucketStart[i];
+            final long curEnd = curStart + bucketDuration;
+
+            // bucket is older than record; we're finished
+            if (curEnd < start) break;
+            // bucket is newer than record; keep looking
+            if (curStart > end) continue;
+
+            final long overlap = Math.min(curEnd, end) - Math.max(curStart, start);
+            if (overlap > 0) {
+                rx += this.rx[i] * overlap / bucketDuration;
+                tx += this.tx[i] * overlap / bucketDuration;
+            }
+        }
+
+        outTotal[0] = rx;
+        outTotal[1] = tx;
+    }
+
     /**
      * @deprecated only for temporary testing
      */
diff --git a/services/java/com/android/server/net/NetworkStatsService.java b/services/java/com/android/server/net/NetworkStatsService.java
index 967e491449..3892de8131 100644
--- a/services/java/com/android/server/net/NetworkStatsService.java
+++ b/services/java/com/android/server/net/NetworkStatsService.java
@@ -210,7 +210,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
             for (InterfaceIdentity ident : mSummaryStats.keySet()) {
                 final NetworkStatsHistory history = mSummaryStats.get(ident);
                 if (ident.matchesTemplate(networkTemplate, subscriberId)) {
-                    // TODO: combine all matching history data into a single history
+                    combined.recordEntireHistory(history);
                 }
             }
             return combined;
@@ -231,8 +231,21 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         // TODO: create relaxed permission for reading stats
         mContext.enforceCallingOrSelfPermission(UPDATE_DEVICE_STATS, TAG);
 
-        // TODO: total UID-granularity usage between time range
-        return null;
+        // TODO: apply networktemplate once granular uid stats are stored.
+
+        synchronized (mStatsLock) {
+            final int size = mDetailStats.size();
+            final NetworkStats.Builder stats = new NetworkStats.Builder(end - start, size);
+
+            final long[] total = new long[2];
+            for (int i = 0; i < size; i++) {
+                final int uid = mDetailStats.keyAt(i);
+                final NetworkStatsHistory history = mDetailStats.valueAt(i);
+                history.getTotalData(start, end, total);
+                stats.addEntry(IFACE_ALL, uid, total[0], total[1]);
+            }
+            return stats.build();
+        }
     }
 
     /**