diff --git a/web/gui2/src/main/webapp/app/fw/layer/loading.service.ts b/web/gui2/src/main/webapp/app/fw/layer/loading.service.ts
new file mode 100644
index 0000000..6c31f15
--- /dev/null
+++ b/web/gui2/src/main/webapp/app/fw/layer/loading.service.ts
@@ -0,0 +1,135 @@
+/*
+ *  Copyright 2015-present Open Networking Foundation
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+import { Injectable } from '@angular/core';
+import { FnService } from '../util/fn.service';
+import { LogService } from '../../log.service';
+import { ThemeService } from '../util/theme.service';
+import { WebSocketService } from '../remote/websocket.service';
+import * as d3 from 'd3';
+
+const id = 'loading-anim';
+const dir = 'data/img/loading/';
+const pfx = '/load-';
+const nImgs = 16;
+const speed = 100;
+const waitDelay = 500;
+
+
+/**
+ * ONOS GUI -- Layer -- Loading Service
+ *
+ * Provides a mechanism to start/stop the loading animation, center screen.
+ */
+@Injectable()
+export class LoadingService {
+    images: any[] = [];
+    idx: number = 0;
+    img: any;
+    theme: string;
+    task: any;
+    wait: number;
+
+    constructor(
+        private fs: FnService,
+        private log: LogService,
+        private ts: ThemeService,
+        private wss: WebSocketService
+    ) {
+        this.preloadImages();
+        this.log.debug('LoadingService constructed');
+    }
+
+    dbg(...args) {
+        this.fs.debug(this.constructor.name, args);
+    }
+
+    preloadImages() {
+        let idx: number;
+
+        this.dbg('preload images start...');
+        for (idx=1; idx<=nImgs; idx++) {
+            this.addImg('light', idx);
+            this.addImg('dark', idx);
+        }
+        this.dbg('preload images DONE!', this.images);
+    }
+
+    addImg(theme: string, idx: number) {
+        let img = new Image();
+        img.src = this.fname(idx, theme);
+        this.images.push(img);
+    }
+
+    fname(i: number, theme: string) {
+        const z = i > 9 ? '' : '0';
+        return dir + theme + pfx + z + i + '.png';
+    }
+
+    nextFrame() {
+        this.idx = this.idx === 16 ? 1 : this.idx + 1;
+        this.img.attr('src', this.fname(this.idx, this.theme));
+    }
+
+    // start displaying 'loading...' animation (idempotent)
+    startAnim() {
+        this.dbg('start ANIMATION');
+        this.theme = this.ts.getTheme();
+        let div = d3.select('#'+id);
+        if (div.empty()) {
+            div = d3.select('body')
+                .append('div')
+                .attr('id', id);
+            this.img = div
+                .append('img')
+                .attr('src', this.fname(1, this.theme));
+            this.idx = 1;
+            this.task = setInterval(() => this.nextFrame(), speed);
+        }
+    }
+
+    // stop displaying 'loading...' animation (idempotent)
+    stopAnim() {
+        this.dbg('*stop* ANIMATION');
+        if (this.task) {
+            clearInterval(this.task);
+            this.task = null;
+        }
+        d3.select('#'+id).remove();
+    }
+
+    // schedule function to start animation in the future
+    start() {
+        this.dbg('start (schedule)');
+        this.wait = setTimeout(this.startAnim(), waitDelay);
+    }
+
+    // cancel future start, if any; stop the animation
+    stop() {
+        if (this.wait) {
+            this.dbg('start CANCELED');
+            clearTimeout(this.wait);
+            this.wait = null;
+        }
+        this.stopAnim();
+    }
+
+    // return true if start() has been called but not stop()
+    waiting() {
+        return !!this.wait;
+    }
+
+
+}