Recently, the TCPIIP protocols are widely used and it is mentioned that, in some cases, throughput is limited due to problems such as network congestion. To solve such problems, the details of communication need to be examined. In order to support these examinations, we are developing an 'intelligent' protocol monitor which can estimate what communication has taken place by emulating the behaviors of the TCP protocol entities in a pair of communicating computers. This paper describes the overview of the monitor and the detailed design of the TCP behavior emulation function for both the state transition based behaviors and the internal procedures for the flow control, such as the slow start algorithm.

Recently, indoor location-based services (LBS) have become attractive with the rapid development of indoor location estimation and with the spread of smartphones. An estimation technique using Bluetooth low energy (BLE) tags becomes most attractive and promising among other techniques for estimating location because a majority of smartphones supports BLE. The BLE tags transmit advertisement (ADV) packets periodically, which include a unique ID related to each tag. When a smartphone receives the ADV packet, the smartphone sends a query to the server to retrieve the locationbased information for the ID. To provide such a service continuously, operators have to monitor whether BLE tags work well and repair them in the event of a problem. These operations are difficult because they require physical labor that cannot be automated for a large number of BLE tags spread over a wide area. Therefore, we evaluated the operations of BLE tags quantitatively by the metric of operational costs. We established an environment composed of 54 BLE tags in a four-story building and measured the lifetime of the battery, the service availability ratio, and the operational costs. Through the experiments, we obtained various results regarding the battery management of the BLE tags and the effectiveness of redundant deployment.

Recently, the TCP/IP protocols are widely used and it is mentioned that, in some cases, throughput is limited due to problems such as network congestion. To solve such problems, the details of communication need to be examined. In order to support such examination, we are developing an 'intelligent' protocol analyzer which can estimate what communication has taken place by emulating the behaviors of the TCP protocol entity in a pair of communicating computers. Since modem TCP includes some internal procedures for the flow control, such as the slow start algorithm, this analyzer can emulate these procedures as well as the state transition based behaviors of the basic TCP. This paper describes the overview of the analyzer, the detailed design of the TCP behavior emulation function and the implementation results.

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