Leo Patanapongpibul

Femtocell access control strategy in UMTS and LTE

Femtocells have become an attractive device for operators to offer extended services on their licensed UMTS/LTE spectrum. In this article we focus on the access control strategy - a crucial aspect for operators to give preferential access to femtocells for their subscribers. The general issue of supporting femtocells in pre-Release 8 UMTS networks with pre-Release 8 UE is first outlined in order to help the reader understand the motivation behind some concepts introduced in 3GPP Release 8 to support femtocells. A description of the femtocell access control strategy for UMTS and LTE is then provided based on 3GPP Release 8 specifications. Finally, the issue of LTE physical cell identity confusion associated with inbound handover to femtocells (which is expected to be resolved within the 3GPP Release 9 timeline) is discussed.

CIRCUIT SWITCHED FALLBACK

ユーザ機器（ＵＥ）のための回路交換フォールバック（ＣＳＦＢ）を促進するための技術が開示される。 モビリティ管理エンティティ（ＭＭＥ）は、ＵＥから最適化ＣＳＦＢ機能インジケータを受信することができる。 ＭＭＥは、ＵＥに関連付けられた要求されるサービスタイプを受信することができる。 ＭＭＥは、ＵＥの最適化ＣＳＦＢ機能に基づいて、回路交換ネットワークへのＵＥの単一無線音声通信継続（ＳＲＶＣＣ）ハンドオーバを開始することができる。 ＭＭＥは、Ｓ１アプリケーションプロトコル（Ｓ１−ＡＰ）要求メッセージを進化型ノードＢ（ｅＮＢ）に送信することができる。 Ｓ１−ＡＰメッセージは、最適化ＣＳＦＢ機能インジケータ及びＵＥのための単一無線音声通信継続（ＳＲＶＣＣ）インジケータを含み得る。 ＭＭＥは、ｅＮＢからハンドオーバ要求メッセージを受信することができる。

GSM/GPRS Bearers Efficiency Analysis for Machine Type Communications

Short Message Service (SMS) over circuit switched (CS), Unstructured Supplementary Service Data (USSD) and GPRS are the main bearers to support different Machine Type Communications (MTC) over a 2G network. Communications of a large amount of Machine to Machine (M2M) terminals may have a significant impact on worldwide deployed 2G networks. This paper compares the efficiency for each of the 2G bearers when M2M terminals perform mobile originated (MO) data calls under a predefined M2M application. The efficiency of each bearer is evaluated at Layers 2 (L2) and 3 (L3) by the ratio of user data payload to the total L3 messages and by the amount of M2M terminals the radio interface can support within one hour. Results show that USSD is the most efficient bearer in L3. When considering L2 messages in radio interface, GPRS proves to be the most efficient bearer.