## 2 Related Works  
### Preterm Prevention Monitoring System  
As mentioned earlier, [PERSON] et al. [6] proposed the electrohysterogram (EHG, uterine EMG) monitoring system for sensing the EMG signals of the mother and sending them to the health device through wireless communication. The key specific features are depicted in Figure 1, which is taken from [PERSON]'s patent [6].  
A surface sensor, which comprises multiple leads, is attached to the uterine surface of the mother (Figures 1a-d and 3a,b). Sensed signals are then sent through the wired network (shown as analog-to-digital convertible shielded cables 4 and 5 in Figure 1) or through a wireless network to the personal health device (shown as 6 in Figure 1), to spatially depict the contraction status (shown as 7 in Figure 1) in real-time. The proposed solution in this study was developed to support the seamless networking of such EMG information monitoring systems, which will be specifically presented in Section 3.  
Limited Bandwidth in Practical Real-Time Wireless Communication and Insufficient Battery Life in Pre-Term Monitoring  
When using 12 channels, a 32-bit resolution, and a 20 Hz EMG monitoring environment, approximately 7.6 Kbps of bandwidth is required. Considering Bluetooth 4.2. (recent version of Bluetooth), its Low Energy (BLE) specifications are appropriate for monitoring situations, mainly because of its low energy consumption. BLE's throughput specification supports up to 7 Kbps [9]. This is a huge lack of network bandwidth because, realistically, 100% of the 7 Kbps cannot be allocated to EMG channels alone. Headers, security, error correction, and other kinds of data (maybe even other signals than EMG) inevitably take up a considerable portion, even when 100% of the portion alone is not enough for the EMG transmission itself.  
Furthermore, in wireless sensor networks, sensors are continuously strained in order to support a seamless network. Engineers are constantly working to increase the run-time of such battery-powered devices [10], because their seamless connection is especially important in smart healthcare networks. However, the need for EMG transmission and a long monitoring length are still large barriers for wireless communications in pre-term monitoring.  
It is optimal for a maternal EMG to be monitored for 40 full weeks during the gestation period. At least the 12 weeks (=40 weeks of full period 28 weeks of extremely pre-term period, refer to Section 2.4) before birth should be monitored in real-time, in order to react within the \"Golden time\". Considering 12 channels, a 32-bit resolution, and a 20 Hz transmission network environment, a minimum of approximately 6.9 Giga Bytes (GB) to a maximum of 23.2 GB of data must be transferred or stored per patient of maternity.  
This is affected by the number of maternity patients supported, meaning that an immense amount of data must be transferred and stored for long periods. In reality, this is a great overload to any wireless transmission situation, both to the device and the network.  
Therefore, this overloaded environment is practically impossible to support. Heavy battery consumption near wireless networks such as Bluetooth or Wi-Fi suffer from network shortages. Large quantities of EMG data take longer to transmit, and monitoring the pre-term status requires lengthy monitoring periods, resulting in immense battery consumption. If the data size can be reduced, wireless transmission network overload will be lowered and the battery life-span will be increased.  
We proposed an algorithm solution to transmit data in a compact size in real-time, thereby contributing to lessening the strains in the wireless communication bandwidth and data transmission strains in battery consumption.