In recent years, cellular networks have witnessed tremendous growth in the use of SMS. In the near future, Multimedia Messaging Service (MMS) is expected to surpass SMS in popularity, traffic, and revenue due to is richer multimedia content such as audio, image and video and greater flexibility. Yet, research in this area has generally been limited, and little is known about the user behavior and system characteristics of mobile messaging. System characteristics based on traces that were collected over the course of three weeks from a nation-wide cellular provider in India that serves over 10 million subscribers. Both message-level and conversation-level messages are characterized, and measurements are presented for person-to-person as well as value-added application-to- person, and person-to-application services. The past decade has witnessed tremendous growth in mobile subscribers, which sequentially has increased awareness of the data capabilities of mobile phones in the market. Although MMS and GPRS based IM are becoming popular, SMS is the most popular data service for cell phones. Today over 200 billion messages are exchanged among worldwide subscribers each month.