diff --git a/lib/modem.js b/lib/modem.js
index 31b4e83..1c32877 100644
--- a/lib/modem.js
+++ b/lib/modem.js
@@ -14,8 +14,10 @@ const mutex = require('./mutex');
 const common = require('./common');
 const sms = require('./sms');
 
-let imsi;
-let signalStrength;
+const modemInfo = {
+    imsi: null,
+    signalStrength: null,
+};
 
 const port = new SerialPort(config.modem.device, { baudRate: 115200 });
 
@@ -82,8 +84,8 @@ parserReadLine.on('data', (data) => {
     logger.verbose(`* IN: ${data}`);
     if (data) {
         if (data.indexOf('+CSQ: ') === 0) {
-            signalStrength = common.extractValueFromReadLineData(data);
-            logger.info(`Signal strength: ${signalStrength}`);
+            modemInfo.signalStrength = common.extractValueFromReadLineData(data);
+            logger.info(`Signal strength: ${modemInfo.signalStrength}`);
         } else if (data.indexOf('+CMTI: ') === 0) {
             onIncomingSMS(data);
         }
@@ -99,8 +101,8 @@ async function readIMSI() {
     const parserReadIMSI = new ParserDelimiter({ delimiter: DELIMITER_WAIT_FOR_OK });
     parserReadIMSI.on('data', (data) => {
         if (data) {
-            imsi = data.toString().trim();
-            logger.info(`IMSI: ${imsi}`);
+            modemInfo.imsi = data.toString().trim();
+            logger.info(`IMSI: ${modemInfo.imsi}`);
         }
 
         mutex.releaseLockWaitForOK();
@@ -175,4 +177,5 @@ function init() {
 
 init();
 
+exports.modemInfo = modemInfo;
 exports.sendSMS = sendSMS;