diff --git a/layers/cellular.js b/layers/cellular.js
new file mode 100644
index 0000000..90481be
--- /dev/null
+++ b/layers/cellular.js
@@ -0,0 +1,127 @@
+import { XYZ } from 'ol/source.js';
+import TileLayer from 'ol/layer/Tile';
+
+// from https://stackoverflow.com/q/32454234
+var quadkey = function (x, y, z) {
+    var quadKey = [];
+    for (var i = z; i > 0; i--) {
+        var digit = '0';
+        var mask = 1 << (i - 1);
+        if ((x & mask) != 0) {
+            digit++;
+        }
+        if ((y & mask) != 0) {
+            digit++;
+            digit++;
+        }
+        quadKey.push(digit);
+    }
+    return quadKey.join('');
+};
+
+const cellular_layers = {
+    name: "Cellular Providers",
+    layers: [
+        // {
+        //     name: "Verizon",
+        //     // enabled: true,
+        //     layer: new VectorTileLayer({
+        //         source: new VectorTileSource({
+        //             format: new MVT(),
+        //             // https://api.mapbox.com/v4/gismaps.3knn09ds,gismaps.2x81tn8t,mapbox.mapbox-streets-v8,gismaps.aq7mk519,mapbox.country-boundaries-v1,gismaps.cbihlc9h,gismaps.7is2087g,gismaps.8hjkv530/7/31/46.vector.pbf
+        //             // url: 'https://basemaps.arcgis.com/arcgis/rest/services/World_Basemap_v2/VectorTileServer/tile/{z}/{y}/{x}.pbf',
+        //             url: 'https://api.mapbox.com/v4/gismaps.3knn09ds,gismaps.2x81tn8t,mapbox.mapbox-streets-v8,gismaps.aq7mk519,mapbox.country-boundaries-v1,gismaps.cbihlc9h,gismaps.7is2087g,gismaps.8hjkv530/{z}/{y}/{x}.pbf'
+        //         }),
+        //     }),
+        // },
+        {
+            name: "AT&T Domestic",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0];
+                        var x = tileCoord[1];
+                        var y = tileCoord[2];
+                        return "https://geolink-igw.cloud.att.com/mapservice/quadkeytile?layer=attDomestic&quadkey=" + quadkey(x, y, z);
+                    },
+                }),
+            }),
+        },
+        {
+            name: "AT&T Prepaid",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0];
+                        var x = tileCoord[1];
+                        var y = tileCoord[2];
+                        return "https://geolink-igw.cloud.att.com/mapservice/quadkeytile?layer=attPrepaid&quadkey=" + quadkey(x, y, z);
+                    },
+                }),
+            }),
+        },
+        {
+            name: "AT&T International",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0];
+                        var x = tileCoord[1];
+                        var y = tileCoord[2];
+                        return "https://geolink-igw.cloud.att.com/mapservice/quadkeytile?layer=attIntl&quadkey=" + quadkey(x, y, z);
+                    },
+                }),
+            }),
+        },
+        {
+            name: "Sprint 5G? (may also be T-Mo now); see <a href='https://coverage.sprint.com/IMPACT.jsp'>Sprint</a> for legends",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    // url: 'https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_5G/{z}/{x}:{y}/tile.png'
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0]+1;
+                        var x = tileCoord[1]+1;
+                        var y = tileCoord[2]+1;
+                        return `https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_5G/${z}/${x}:${y}/tile.png`;
+                    },
+                }),
+            }),
+        },
+        {
+            name: "Sprint LTE? (may also be T-Mo now)",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    // url: 'https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_lte/{z}/{x}:{y}/tile.png'
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0]+1;
+                        var x = tileCoord[1]+1;
+                        var y = tileCoord[2]+1;
+                        return `https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_lte/${z}/${x}:${y}/tile.png`;
+                    },
+                }),
+            }),
+        },
+        {
+            name: "Sprint non-LTE? (may also be T-Mo now)",
+            layer: new TileLayer({
+                opacity: 0.5,
+                source: new XYZ({
+                    // url: 'https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_5G/{z}/{x}:{y}/tile.png'
+                    tileUrlFunction: function (tileCoord, pixelRatio, projection) {
+                        var z = tileCoord[0]+1;
+                        var x = tileCoord[1]+1;
+                        var y = tileCoord[2]+1;
+                        return `https://coverage.sprint.com/MapTile/5GDataMap/Tiles/data_xp_3G/${z}/${x}:${y}/tile.png`;
+                    },
+                }),
+            }),
+        },
+    ],
+};
+
+export default cellular_layers;
diff --git a/layers/index.js b/layers/index.js
index eef17c8..59ca460 100644
--- a/layers/index.js
+++ b/layers/index.js
@@ -10,6 +10,8 @@ import chains from './chains/index.js';
 import census_bureau from './census-bureau/index.js';
 import states from './states/index.js';
 import national_land from './national-land/index.js';
+import cellular from './cellular.js';
+import light_pollution from './light_pollution.js';
 
 const layerCategories = [
     { // Base maps
@@ -77,6 +79,8 @@ const layerCategories = [
     census_bureau,
     states,
     national_land,
+    cellular,
+    light_pollution,
 ];
 
 export default layerCategories;
diff --git a/layers/light_pollution.js b/layers/light_pollution.js
new file mode 100644
index 0000000..21a5a3d
--- /dev/null
+++ b/layers/light_pollution.js
@@ -0,0 +1,28 @@
+import { XYZ } from 'ol/source.js';
+import TileLayer from 'ol/layer/Tile';
+
+let layers = [];
+
+["2006", "2016", "2020"].forEach(year => {
+    layers.push({
+        name: `<a href='https://djlorenz.github.io/astronomy/lp${year}/'>djlorenz ${year}</a>`,
+        layer:
+        new TileLayer({
+            source: new XYZ({
+                attributions: `David Lorenz's <a href=http://djlorenz.github.io/astronomy/lp${year}/>Light Pollution Atlas ${year}</a>`,
+                maxZoom: 6,
+                tilePixelRatio:4,
+                tileSize: (1024, 1024),
+                transition: 0,
+                url: `https://djlorenz.github.io/astronomy/lp${year}/overlay/tiles/tile_{z}_{x}_{y}.png`,
+            }),
+            visible:true,
+            opacity: 0.5,
+        }),
+    });
+});
+
+export default {
+    name: "Light Pollution",
+    layers: layers,
+};