Cognitive radio Either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with.

Presentation on theme: "Cognitive radio Either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with."— Presentation transcript:

1 A cognitive radio system for E-health applications in a hospital environment

2 Cognitive radio Either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with users This alteration of parameters is based on the active monitoring of several factors in the external and internal radio environment 인지무선:전파 환경을 측정하여 측정된 전파 환경에 적합하게 무선 기기의 운용 파라미터를 설정하여 동작하는 무선 기술. 예를 들어 무선 기기의 전송 용량을 채널 특성에 맞게 최대화, 기기 간 간섭 최소화, 다른 기종 시스템 간에 상호 동작성 촉진, 또는 비사용 주파수를 찾아서 1차 사용자가 사용하지 않는 시간에 이용하는 기술이 모두 이 범주에 속한다.

3 Abstract & Introduction
Challenges - Electromagnetic interference (EMI) - Different types of e-health applications have different priorities Wireless communication - improve mobility - service flexibility - medical devices are sensitive to EMI - quality of service (QoS) 인지무선:전파 환경을 측정하여 측정된 전파 환경에 적합하게 무선 기기의 운용 파라미터를 설정하여 동작하는 무선 기술. 예를 들어 무선 기기의 전송 용량을 채널 특성에 맞게 최대화, 기기 간 간섭 최소화, 다른 기종 시스템 간에 상호 동작성 촉진, 또는 비사용 주파수를 찾아서 1차 사용자가 사용하지 않는 시간에 이용하는 기술이 모두 이 범주에 속한다.

4 Telemedicine applications - packet delay and packet loss
Hospital information system applications - packet loss Telemedicine > Hospital information system primary secondary QoS(Quality of Service)는 다른 응용 프로그램, 사용자, 데이터 흐름의 우선 순위를 정하거나 데이트 전송에 특정 수준의 성능을 보장하기 위한 능력을 말한다

5 Requirements for wireless communications systems
Electromagnetic compatibility (EMC) - limit the transmit power Quality of service (QoS) - IEEE e Coexistence of different wireless technology Seamless connectivity - Mobility management Security of healthcare data QoS 향상 목적으로 IEEE e가 새로 제안한 채널 접속 방식은 HCF(Hybrid Coordination Function)이다.  HCF는 EDCF(Enhanced DCF)라는 경쟁 기반의 채널 접속 방식과 폴링 방식(Polled Channel Access)을 함께 사용한다.

6 Cognitive radio for E-health application
Objectives - avoid harmful EMI - provide QoS differentiation Horizontal spectrum sharing - unlicensed band Vertical spectrum sharing - licensed band >Wireless medical telemetry service (WMTS) – external human body, 14 MHz >Medical implant communications service (MICS) – inside the human body, MHz - Intensive care units (ICUs) - wireless transmission parameters must be carefully chosen Operate either unlicensed or licensed

7 Channel access - spectrum overlay A secondary user uses a channel from a primary user only when it is not occupied - spectrum underlay The primary users deploy systems with a much higher power density level

8 Architecture of the cognitive radio system for E-health applications
Consists of - inventory system - controller - clients Operates - control channel and data channel - unlicensed spectrum band - interference avoidance approach

9 Architecture of the cognitive radio system for E-health applications
Inventory system - be supported by tracking system Controller - compute the appropriate transmission parameters - uses two radio interfaces >control channel and data channel Clients - be controlled by the cognitive radio controller - use one radio interface > one channel at a time

10 Channel allocation and access
Common control channel broadcasting - - radio frequency range: 800MHz-2.5GHz every time slots, and are broadcast

11 EMI-aware RTS/CTS protocol

12 Data transmission and queue management - user switches its radio from control channel to data channel - two queues are used at the controller >primary and secondary - if the transmission queue is full, the user’s request will be dropped >considered to be a collision

13 Numerical results

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