Abstract To explore the feasibility of high‐frequency indoor wireless body area network (WBAN) communications, the propagation characteristics of WBAN in simulated hospital ward scenarios at 11 GHz are studied. Based on the extensive measured data, the impact of the patient's lying angle (LA) on channel characteristics has been analyzed, such as statistical characteristics of path loss (PL), shadowing effect, and root mean square delay spread. Moreover, a PL model with LA factor is presented for the hospital ward scene, and the influence of LA on PL in the presence of height difference is also analyzed. The research results indicate that, the PL caused by LA (abbreviated as P LA ) follows a power function with respect to the LA in case of a fixed distance between the transmitter and receiver. When the LA is fixed, P LA exhibits a cubic function relationship with the distance between the transmitter and receiver. In addition, the presence of patient's LA can cause more significant multipath effect. However, the impact of LA gradually weakens as the height difference increases when there is a height difference. The research results provide a theoretical basis and practical basis for utilizing the 11 GHz frequency band in indoor WBAN in the future.

SQLite, one of the most popular light-weighted database system, has been widely used in various systems. However, the compact design of SQLite did not make enough consideration on user data security. Specifically, anyone who has obtained the access to the database file will be able to read or tamper the data. Existing encryption-based solutions can only protect data on storage, while still exposing data when in computation. In this article, we combine the Trusted Execution Environment(TEE) technology and the authenticated encryption scheme, proposed and developed the CryptSQLite, a high security SQLite database system, which protects both the confidentiality and integrity of users' data. Our security analysis proves that CryptSQLite can protect data confidentiality and integrity. Our implementation and experiments indicate that CryptSQLite incurs an average of 21 percent of extra time for SQL statement executions, compared with traditional encryption-based solutions that failed to offer rigorous security guarantees.