Design of Wireless Communication Networks for Cyber-Physical Systems with Application to Smart Grid

Cyber-Physical Systems (CPS) are the next generation of engineered systems in which computing, communication, and control technologies are tightly integrated. On one hand, CPS are generally large with components spatially distributed in physical world that has lots of dynamics; on the other hand, CPS are connected, and must be robust and responsive. Smart electric grid, smart transportation system are examples of emerging CPS that have significant and far-reaching impact on our daily life. In this dissertation, we design wireless communication system for CPS. To make CPS robust and responsive, it is critical to have a communication subsystem that is reliable, adaptive, and scalable. Our design uses a layered structure, which includes physical layer, multiple access layer, network layer, and application layer. Emphases are placed on multiple access and network layer. At multiple access layer, we have designed three approaches, namely compressed multiple access, sample-contention multiple access, and prioritized multiple access, for reliable and selective multiple access. At network layer, we focus on the problem of creating reliable route, with service interruption anticipated. We propose two methods: the first method is a centralized one that creates backup path around zones posing high interruption risk; the other method is a distributed one that utilizes Ant Colony Optimization (ACO) and positive feedback, and is able to update multipath dynamically. Applications are treated as subscribers to the data service provided by the communication system. Their data quality requirements and Quality of Service (QoS) feedback are incorporated into cross-layer optimization in our design. We have evaluated our design through both simulation and testbed. Our design demonstrates desired reliability, scalability and timeliness in data transmission. Performance gain is observed over conventional approaches as such random access

Utilizing Supported Band Grouping and Display of Partial Search Results to Expedite Manual PLMN Selection Procedure

This publication describes techniques and apparatuses that expedite the procedure for manual (“on-demand”) Public Land Mobile Network (PLMN) selection by a user using a user equipment (UE). To create a PLMN search priority when performing a manual PLMN selection procedure, the process is divided into a system information database (SI DB), a mobile country code database (MCC DB), and a Remainder database (Remainder DB). The SI DB includes a predefined number (e.g., ten) of the last absolute radio-frequency channel numbers (ARFCN) acquired on each radio access technology (RAT). The MCC DB is a band of frequencies identifying the PLMN location by country (e.g., the United States of America, Australia, Germany). The Remainder DB groups a band of frequencies that are not in the MCC DB. When the user initiates the manual PLMN selection procedure, the UE searches for available PLMNs according to a grouping priority, in three phases: an SI DB, an MCC DB, and a Remainder DB search phase. The user receives periodic updates on the available PLMN list, and the user, at any time, can select the target PLMN without needing to wait for the UE to complete the whole search process

Estimating Probability of Stable Service for a Successful Voice Call Origination

A user of a device is provided with a notification indicating an estimate of a probability of success of a call on a cellular network prior to originating the call. With this notification the user may be aware that the device is in an area where the call may not be successfully connected, or the call may be disconnected due to the signaling conditions. The user then may elect to either continue attempting to establish the call, or to delay the call until the user is in a location more likely to lead to successful call origination

Public Land Mobile Network Selection During International Roaming

This publication describes techniques and apparatuses directed to Public Land Mobile Network (PLMN) selection during international roaming. In aspects, roaming activity data is collected and compiled into a database of roaming activity data of Home PLMNs and associated Roaming PLMNs. The Roaming PLMNs are Visited PLMNs operated by a roaming partner that a subscriber’s operator has a roaming agreement with. An Optimized Preferred PLMN List (OPPL) is created from the compiled roaming activity data and the OPPL is stored on user equipment (UE). During international roaming, the UE can utilize the OPPL to determine a suitable PLMN for which to attempt registration, thereby avoiding the time and resources spent attempting to register to a randomly selected neighboring PLMN

1 Compressed Meter Reading for Delay-sensitive and Secure Load Report in Smart Grid

Abstract — It is a key task in smart grid to send the readings of smart meters to an access point (AP) in a wireless manner. The requirements of scalability, realtimeness and security make the wireless meter reading highly challenging. On assuming that the number of smart meters is large and the data burst is sparse, i.e., only a small fraction of the smart meters are reporting their power loads at the same time, the technique of compressed sensing is applied for the wireless meter reading. The distinguishing feature of the compressed meter reading is that the active smart meters are allowed to transmit simultaneously and the AP is able to distinguish the reports from different smart meters. The data sparsity solves the problem of scalability. The simultaneous access results in uniform delays, in contrast to the possible large delay in carrier sensing multiple access (CSMA) technique. The random sequence used in the compressed sensing enhances the privacy and integrity of the meter reading. The validity of the proposed scheme is then demonstrated by numerical simulations. I