Manual de Procedimientos para la Recuperación de Cartera

The state-of-the art MAC protocols are analysed focusing on IBSN and BSN. Different pro- tocols have unique features exactly suited for the IBSN applications, and at the same time drawbacks which renders the MAC protocols not completely useful. In order to exhibit this contradiction in selecting a best suited protocol, Table 3.9 presents an overall comparison of all the protocols studied. In general for the purpose of the IBSN, certain features are considered for a reliable performance. It is important to select characteristic features that are most important for the operation of Implantable sensor nodes.

The features that are selected for this comparison are based on the requirements from Sec- tion 2.4 and common added values of the MAC protocols studied:

• Low latency

• Hardware complexity

– Frequency of operation

– Bandwidth utilization

– Effective radiated power

• Energy efficiency

– Duty cycle

– Energy aware operation of main radio and wake-up radio.

• Software overhead

– Headers for link establishment

– Cross-layer features

– Higher payload data per frame

• Reliability

CHAPTER 3. SURVEY OF MAC PROTOCOLS WITH AND WITHOUT WAKE-UP RADIO FOR IMPLANTABLE SENSOR NETWORK

– Packet delivery ratio

– Retransmission mechanism and redundancy in data retransmission.

• Effective throughput

– Data rate

– Higher payload

• Quality of Service

More than 40 protocols have been considered in order to broadly evaluate their use in IBSN. A + indicates that the specific feature is an advantage for IBSN and a − indicates that the feature is a disadvantage for IBSN. Table 3.9 is a classification of different protocols based on network features such as mentioned in the list.The choice analysing the MAC protocols based on the specific network parameters is explained below.

Energy efficiency is the overall consumption of energy of a sensor node in establishing a link

for data transfer. A MAC protocol determines the energy efficiency by controlling the access to the wireless medium. A efficient MAC protocol should have minimum access to the wireless medium and at the same time not compromising the performance of the underlying network. In a complex IBSN, the longevity of the network is decided by the power available. Hence, analysing the MAC protocol based on the energy efficiency and identifying the major design flaw in existing design is important. Reliability is the successful data transfer from a Tx node to a Rx node. Reliable MAC protocols typically incur more overhead than unreliable protocols, and as a result, are slower and less scalable. This is not an issue for star-topology based unicast communication in IBSN. Analysis of reliability is to ensure that all the emergency data can be communicated to the base station, while not compromising the energy efficiency. In a networkSoftware overhead

is the non-useful data which is used to successfully establish a link between Tx and Rx. In order to understand the how the reliability is affected with software overhead, each protocol have been evaluated with the software overhead incurred in each protocol. Quality of Service parameters considered in this analysis include error rate, bandwidth, throughput and transmission delay. In IBSN, the MAC protocol may not provide all the QoS features, but knowing the dependency of the QoS with energy efficiency and reliability is important. Latency is the amount of time required to establish a link before any useful data transfer. In case of IBSN, latency of upto 60 ms can be tolerated [3]. However, increase in latency directly affects the reliability and network failure if a time critical application is considered. The main reasons for the latency in a network can be due to the path loss and RF interferences. But latency due to overheads can also be a reason in some of the MAC protocols as discussed in section 3.4.1. Thus, considering the IBSN scenario it is important that the latency needs to be evaluated for a given access mechanism.

Hardware complexityis hardware components that are required for establishing a link in wireless

medium, for example, a extra transceiver is required in case of wake-up radio mechanisms apart from the main radio transceiver.

All the MAC protocol mentioned in the table 3.9 are focussed on the IBSN application scenario, while none of them is explicitly developed for IBSN applications. Although some of the protocols are developed for general WSN application, it is still considered since, the features of the protocol also meet the requirement of the IBSN application. Table 3.9 is a qualitative analysis of the protocols based on the requirements of IBSN application.

MAC protocol Features Energy- efficiency Reliability Software- overhead Effective- throughput QoS Low- latency Hardware complexity CF-MAC[38] Y-2005

+ + + ++ + + + + −− + TDMA w/o WuR SSD-TDMA [76]

Y-2005

+ + + −− − + + + −− + + + TDMA w/o WuR DQBAN MAC[40]

Y-2009

−− − + + + + − − TDMA w/o WuR HEH-MAC [41]

Y-2007

−− + −− ++ −− + + + TDMA w/o WuR BodyMAC [37]

Y-2009

+ + + + −− ++ −− −− TDMA w/o WuR UB-MAC [53]

Y-2010

−− ++ − + + + − + + + TDMA+CSMA w/o WuR X-MAC[50]

Y-2006

+ + + −− ++ −− + + + + TDMA+CSMA w/o WuR V-MAC [51]

Y-2008

+ −− + + + − − − − ++ TDMA+CSMA w/o WuR R-MAC [52]

Y-2007

+ + + − − + + + − + + + TDMA+CSMA w/o WuR PNP-MAC [49]

Y-2010

− − − + − − − + −− + + + TDMA+CSMA w/o WuR O-MAC [47]

Y-2006

+ + + −− − + + + − + + + TDMA+CSMA w/o WuR MEB-MAC [46]

Y-2012

+ + + + − + + + − ++ TDMA+CSMA w/o WuR EEE-MAC [54]

Y-2013

−− + + + − + + + −− + + + TDMA+CSMA w/o WuR FE-MAC [55]

Y-2007

+ + + −− − + + + − + + + TDMA+CSMA w/o WuR P-MAC [77]

Y-2013

+ −− − + + + − + + + TDMA+CSMA w/o WuR CA-MAC [43]

Y-2009

− − − ++ −− ++ − − − + + + TDMA+CSMA w/o WuR ULP-MAC [44]

Y-2005

+ + + + − − − ++ − − − + + + TDMA+CSMA w/o WuR BMAC [45]

Y-2007

+ + + + − − − ++ − + + + TDMA+CSMA w/o WuR BSN-MAC [39]

Y-2010

+ + + −− ++ + − + + + TDMA+CSMA w/o WuR ULPD-MAC [78]

Y-2008

−− + − + + + − − − − TDMA+CSMA w/o WuR DISSense [48]

Y-2007

+ + + + − − − + + + −− ++ TDMA+CSMA w/o WuR S-MAC[18]

Y-2002

− − − + − − − ++ − + + + TDMA+CSMA w/o WuR

CHAPTER 3. SURVEY OF MAC PROTOCOLS WITH AND WITHOUT WAKE-UP RADIO FOR IMPLANTABLE SENSOR NETWORK

MAC protocol Features Energy- efficiency Reliability Software- overhead Effective- throughput QoS Low- latency Hardware complexity Cooperative - MAC [9] Y-2008

++ + −− ++ −− ++ TDMA+FDMA w/o WuR Hybrid-MAC [58]

Y-2014

− − − + + + − − − + + + −− + + + TDMA+FDMA w/o WuR HyMAC [59]

Y-2012

+ + − − − ++ + ++ TDMA+FDMA w/o WuR

HUA-MAC[39] Y-2010

+ + + ++ − − − ++ −− + + + Hybrid ALOHA w/o WuR YNU-MAC [60]

Y-2009

− + −− ++ ++ −− CSMA + UWB w/o WuR FM-UWB MAC [61]

Y-2009

− ++ −− ++ −− + + + CSMA + UWB w/o WuR NICT-MAC [64]

Y-2014

+ + + + −− ++ −− + + + Slotted ALOHA + WuR IMEC-MAC [65]

Y-2009

+ + + + −− − −− ++ ALOHA + TDMA + WuR Miller-MAC [66]

Y-2005

+ + + + −− − − − −− + + + TDMA+CSMA+ WuR RTWAC[67]

Y-2009

+ + −− + + ++ TDMA+ CSMA + WuR PE-MAC [68]

Y-2011

+ + −− −− −− − − − TDMA+ CSMA + WuR

ULPA-MAC [70] Y-2013 ++ − −− + + + −− − CSMA + WuR WuR MAC [71] Y-2006 + + + ++ −− ++ − + CSMA + WuR T-MAC[72] Y-2003 − ++ −− ++ −− + CSMA + WuR TBCD-TDM [73] Y-2009 + + + + − − − + −− + + + TDMA+WuR

Table 3.9: Comparison of MAC protocols in terms of network parameters